# How To Find Acceleration In A Pulley System With Friction

Last Revised on January 8, 2015 Grade: _____ Experiment 2 Acceleration of Gravity 1. The only force on it is , and it has the acceleration found above. provides the acceleration for an object in a circular motion: F c = ma = m v2 r e. Kinetic friction opposes the motion of the object and is proportional to the normal force acting on an object. The coefficient of kinetic friction between M1 and the ramp is 0. 400) horizontal surface. Calculate the force ratio for a pulley belt on a wheel when it is about to slip given the coefficient of friction is 0. µ k = Part II: Predicting D The distance, D pre, the friction block slides after the launch cart’s (plunger bar. ? Okay so there are a total of three blocks spread across a table. If the pulley has a mass "m", then It has a moment of inertia I which is functiom of mass m. Featuring dual Photogate beams, Laser switch, Photogate tape guide, and capability to daisy chain with either photogate or TIme-of-Flight accessory. If you're seeing this message, it means we're having trouble loading external resources on our website. Two masses of 4. I give eight different situations in which blocks are connected by ropes. Rotation: Moment of Inertia and Torque Every time we push a door open or tighten a bolt using a wrench, we apply a force that results in a rotational motion about a fixed axis. The engineering questions are: The stiffness of the drive is determined by the amount of stretch of the belt between the two pulleys. Use MS Excel to make a graph of “ Acceleration vs Total Mass: Constant Net Force. The 10 kg mass i s the highest mass you can hang without moving the box on the table. When the system is released: a. In other words you can find the mechanical advantage of a pulley system by applying a weight to the system and then determining the amount of. Pulley + Spring combinations - In the third group, our review deals with systems where spring(s) are added to pulleys. Our analysis is based on the system being in static equilibrium, which means that all forces must sum to zero. I want to calculate the minimum required rolling friction that I need (acceleration without slipping) to achieve Stack Exchange Network Stack Exchange network consists of 175 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. The required equations and background reading to solve these problems are given on the friction page, the equilibrium page, and Newton's second law page. Ignoring friction, what is the acceleration of. When this system is released from rest, the pulley turns through 1. The table and pulley are both frictionless. For example, if a constant force exactly equal to the opposing force of friction is applied to a sliding object, the object moves at constant velocity — no acceleration. M T 5 T 4 T 3 T. 5kg by a light inextensible string which lies along a line of greatest slope of the plane and passes over a fixed smooth pulley at the. 1 Newton's 2nd law of motion Hint not displayed Hint C. A rotating mass stores energy. Thus, we can find the force of friction if we can measure both masses and the acceleration of the cart (or equivalently the acceleration of the hanging mass). The rope and the pulleys are massless and there is no friction. The two regimes of dry friction are 'static friction' ("stiction") between non-moving surfaces, and kinetic friction (sometimes called sliding friction or dynamic friction) between moving surfaces. The Atwood's Machine is used below to help in understanding how Newton's 2nd law applies to a system of two connected masses. It is connected by a massless string passing over a massless frictionless pulley to a 0. The post Newton's laws - Acceleration of two masses with a pulley and a spring appeared first on YouPhysics. I want to calculate the minimum required rolling friction that I need (acceleration without slipping) to achieve Stack Exchange Network Stack Exchange network consists of 175 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. The large box on the table is 30 kg and is connected via a rope and pulley to a smaller 10 kg box, which is hanging. 0 kg, and so using Newton's 2 nd law, the acceleration of the system is P F r P 40. The straightforward way to calculate the acceleration is to consider the combined system. Best Answer: apply newton's second laws to each block in the first case, if B descends at constant velocity, the forces acting on it sum to zero, these forces are the weight of B acting down, and the tension of the string, this means that the tension in the string is WB. Find the tension in each segment of the massless ropes and the magnitude of F. The primary types of friction associated with a Pinewood Derby car are the kinetic friction of the axles on the wheels and the static friction of the wheels rolling on the track. Using the Atwood's Machine experimental acceleration data (for 10 different runs with 10 different combinations of masses) will be gathered and compared to the theoretical acceleration which is predicted by Newton's Second Law using a modified version of. The Newton's Second Law experiment provides the student a hands on demonstration of "forces in motion". Use g = 10 m/s2. 74 m s 2 23. Find the acceleration and the speed after 5 seconds. The acceleration of the system and the tension are calculated and the position of the masses at time is shown. Let's say we have a system with a 10 kg weight (m 1) hanging vertically connected by a pulley to a 5 kg weight (m 2) on a 60 degree ramp (assume the ramp is frictionless). 2) Repeat question #1 using a friction coefficient of 0. 2 used to calculate I. 786 14 µ= ≈ A B α P. Concepts: Interacting objects, Newton's laws. Given: since the force of 10N was applied when the body was just about to move, then the static or limiting frictional force, F = 10N. where the T 1 and T 2 are the tensions in the string on either side of the pulley (not equal), I is the moment of inertia of the pulley, t is the retarding torque due to pulley friction and a is the angular acceleration of the pulley. Set up the. The coefficient of kinetic friction between box A and the table is 0. 340-m radius, and is turning at 90. Kinetic friction, also called sliding friction, is a force exerted between two objects in motion relative to one another. You can derive them from the equations we listed above. Instead it is a disk of radius 0. calculate its acceleration. 2 Find an expression for the net external force Hint not displayed Hint C. The coefficient of friction is 0. 1 gram) and record it in the data table in kg. It starts from rest at point A at a height h above the bottom of the loop. N due to the friction between the pulley and its axle If the two mass system from PHYS 1401 at Lone Star College System. The masses of the three blocks are mA = 12. 46: Energy + circular motion. Use the data from Procedure 3. The friction force depends on the mass of an object plus the coefficient of sliding friction between the object and the surface on which it slides. If the string is uneven, the acceleration may not be constant due to non-constant friction. Pulley Problem 8. Worksheet 3. MEASURING PER UNIT INERTIA We should be able to calculate Per Unit Inertia by measuring the ampere-seconds it takes to accelerate the car, then divide by the rated motor amperes. The coefficient of kinetic friction is μ k = 0. The presence of friction and inertia in the pulley modifies the transmitted tension. Do the predictions of Newton's law agree with your results? 3) Compare the slope of the best-fit line through your data with the system mass. At constant speed (no acceleration. 2) Place the wooden stop at the base of the pulley. Calculate the acceleration of the system. Friction involves the string rubbing against the pulley and the blocks moving through air (and possibly the microscopic motions and arrangemnts of atoms within the blocks) and remains external to our system. A fixed pulley is the only pulley that when used individually, uses more effort than the load to lift the load from the ground. Two masses of 4. A bucket with mass m 2 and a block with mass m 1 are hung on a pulley system. Determining the Acceleration of a System of 2 Objects. motor power to lift counter weight at given speed and acceleration? PersonalProfile (Mechanical) 6 Jul 13 03:38 I am struggling with the understanding the practicalities etc, though if neglecting this and inertia (and delta of rope mass and "sheave" friction) of the left hand side, to me the system is balanced and you. 4-part problem; finding acceleration, tension, time, and speed for mass on table to reach pulley while other mass hangs. You can calculate the rate of acceleration, measured in meters per second, based on the time it takes you to go from one velocity to another, or based on the mass of an object. Treating the pulley as a uniform disk, find the downward acceleration of the weight and the tension in the cable. green block of mass m = 1. Find the coefficient of static friction μ S. In a physics lab, Kate and Rob use a hanging mass and pulley system to exert a 2. For an angle of θ = 30. Derive an expression for the acceleration; it should have the form. The total mass is the sum of the two masses and the net force is the difference in the two weights. 0 kg, and the system begins to move just after it is released. Newton's second law says: Where F net is the total force an object, m is the mass and a the acceleration. Part A: Calculate the coefficient of kinetic friction mu between block A and the table top. 0 kg, and so using Newton's 2 nd law, the acceleration of the system is P F r P 40. Thus the weight of a pound where g = 32. • This is an example of static equilibrium. Solve Eqn-1 & Eqn-2 simultaneously for μ k and write the result below in terms of variables. You will then find the acceleration from the. If you already know how to calculate acceleration let's focus on the units of acceleration. Calculate the theoretical value for acceleration, from Equation 2, and the experimental value, from Equation 3. The block lies on a frictionless incline of angle 30 o. Set up the. 2 kg, and the radius of the pulley R = 5. Two objects are sent on a pulley and a theoretical acceleration can be calculated by applying it as a force problem. z˜p = π †d˜ p Round to a whole number of pulley teeth zp. A rope is fastened to a 50. The calculations for example 2 are seen below. Kinetic friction opposes the motion of the object and is proportional to the normal force acting on an object. The fixed pulley when attached to an unmovable object e. If the string is uneven, the acceleration may not be constant due to non-constant friction. 500-kg block; the other end is fixed to a point on the rim of the disk (Fig. A 13 kg block(mA) rests on a level table. 05, mA = 2 kg and mB = 2 kg. Part A: Calculate the coefficient of kinetic friction mu between block A and the table top. 0 rpm, and you press a steel axe against it with a radial force of 20. This will help in the. b) Find the magnitude of the tension in the string. Motion on an inclined plane is a classic application of Newton’s Second Law and free body diagrams. According to Newton's second law an object will accelerate in the direction of the net force. Develop a quantitative understanding of the force, mass, and acceleration relationship. An engineer who wants to design a system so that it has a certain acceleration must be able to calculate the acceleration from the parameters defining the system. Try various values for masses and friction coefficients, see what happens. 0 rpm, and you press a steel axe against it with a radial force of 20. 9m rod w bench edge clamp. 1 gram) and record it in the data table in kg. Find the acceleration of the system, in terms of g. If the masses of blocks A and B were both doubled, what would happen to the acceleration of the system? 7. Find the acceleration of block C. Give the trolley a short and gentle push. Dynamics Exam1 and Problem Solutions 1. Calculate the tension in the string. A Determination of g, the Acceleration Due to Gravity, from Newton's Laws of Motion Objective In the experiment you will determine the cart acceleration, a, and the friction force, f, experimentally for different known masses m 1 and m 2. 00 kg, and mC = 10. Sand is gradually added to the bucket until the system just begins to move. Best Answer: apply newton's second laws to each block in the first case, if B descends at constant velocity, the forces acting on it sum to zero, these forces are the weight of B acting down, and the tension of the string, this means that the tension in the string is WB. 4 Types of Friction, with or without Energy Transfer. running over a pulley. Find the magnitude of the acceleration with which the bucket and the block are moving and the magnitude of the tension force T by which the rope is stressed. Force and Acceleration Objectives In this experiment, you will investigate Newton's second law by using a system of connected masses. If something breaks, you will get a leak, not an explosion. Why is friction a nuiscance in a. 25 and the 8 kg block and is 0. Assume that there is no friction in the given problem. asked by DW on October 1, 2013; Physics. M T 5 T 4 T 3 T. 00 kg are connected by a light string that passes over a frictionless pulley as in Figure P4. B) When two objects are in contact with no relative motion, the magnitude of the frictional force may be either less or equal to. This is not the friction that pushes the automobile. Experiment 4 ~ Newton's Second Law: The Atwood Machine Purpose: To predict the acceleration of an Atwood Machine by applying Newton's 2nd Law and use the predicted acceleration to verify the equations of kinematics with constant acceleration. com always has the largest selection of New or Used Suzuki Motorcycles for sale anywhere. Here is a representative inclined plane problem which ignores the effects of friction. Find the acceleration of all the masses Question: 5. suppose you. Drive Wheel Motor Torque Calculations. The system is then released from rest. The equation for this relationship is: !!=!!!! (1) In order to calculate the coefficient of kinetic friction, consider a simple setup with a block of. 4 m/s2) b) Assuming that block 1 is sliding to the right (toward the pulley), find the tension in the string. time graph where the slope of the graph represents the acceleration of the moving system. They want you to calculate the acceleration of the system. M T 5 T 4 T 3 T. Therefore, to make things simple, we often use the massless and frictionless pulley approximation. 25 and the 8 kg block and is 0. a M = 5kg 2 = 3kg T T. There is a way to find the direction of friction in a given problem. If the system of A and B is released from rest, find (i) The acceleration of A, (ii) Tension in the string, & (iii) The magnitude and the direction of the force of friction acting on A. I have a mass on a low friction track with a string connected over a pulley to a hanging mass. Kate Scholberg. Find the tension in each segment of the massless ropes and the magnitude of F. ) Solution: The magnitude of the acceleration is a=2. to determine the coefficient of friction between belt and pulley; to find coefficient of friction between belt and pulley; what are the factors upon which the coefficient of friction between the belt and the pulley depends; what does a coefficient of friction mean; what does a coefficient of friction tell you; what is standard belt width. The angle of the inclined plane is given, and the coefficient of kinetic friction between mass m2 and the inclined plane is μk=0. Friction can be ignored in this problem. You're dragging a suitcase up a ramp into a luxury hotel when it gets away from you. Rear Pulley. How to solve a system with Three blocks in a pulley system with kinetic friction constant given. Our lab uses the force of gravity in order to find the maximum static friction force on an object before it turns into kinetic friction. At first, we will keep the total mass of the moving system constant throughout the investigation. Taking downward as the positive direction for the hanging mass, the acceleration will be. A massless pulley is attached to the ceiling,in a uniform gravitational field, and rotates with no friction about its pivot. Note you must calculate which will be in radians and convert to turns by dividing the answer by 2. gravity, tension, normal force. The coefficient of friction between the object and the table is 0. In this experiment, since the coefficient of kinetic friction is to be measured, constant speed motion of block M requires a zero acceleration. to find a solution of a system of n-1 equations that have infinite solutions, while in the other two formalisms, we have to solve a. If the object is changing velocity at a constant rate, the object is moving with constant acceleration. kg mass and the horizontal. What is the acceleration of the system?. ” Does the shape of your graph confirm the relationship between acceleration and net force that Newton’s 2nd Law. Determining the acceleration for a pulley on a frictionless table system Determining the acceleration for a pulley on a table system with friction Blocks and Pulley Systems and Tension Force — Determining the acceleration for a pulley on a table system with friction. Sheave or pulley friction factor k, ideal mechanical advantage of the system N & Number of sheaves or pulleys s are. Motion of Two Bodies Connected by a String over a pulley on different planes. The net force on the cart is the tension in the string minus the friction forces. find its way over the pulley. 75 kg object which is released and allowed to fall, pulling the first mass after it. In real situations, there are friction between the string and the pulley. A rope used in a pulley system is configured so two lengths of rope are created with just the one piece. 2 used to calculate I. In order for an object to move, the applied force must overcome the force of static friction. a) Find the tension in the string during the first 1. 00 kg and m2 = 9. provides the acceleration for an object in a circular motion: F c = ma = m v2 r e. A 70 kg box is pulled by a 300 N force at an angle of 300 above the horizontal. The mass m 1 hangs freely and m 2 and m 3 are on a rough horizontal table (the coefficient of friction= ). Find the acceleration and the tension in the rope of the system of masses shown (M > m), neglecting the mass of the string and the inertia of the pulley assume that the static and kinetic friction coefficients are equal to μ 1 μ 2 and the slope angle θ are known. The engineering questions are: The stiffness of the drive is determined by the amount of stretch of the belt between the two pulleys. 2 under bodies B and C. To determine the required motor drive torque for a belt and pulley system, calculate the torque required acceleration, constant velocity, and deceleration. (a) Draw the free-body diagrams for each of the boxes, identifying all of the forces acting on each one. Purpose To determine the relationship between force, mass, and acceleration using a cart attached to a pulley with varying weights. In this part of the experiment, the system is set in motion by the release of the suspended mass. A 7650-kg helicopter accelerates upward at 0. Calculate the force caused by gravity on the basic pulley system using the following equation: G = M x n (gravitational acceleration). Dynamics Exam1 and Problem Solutions 1. Figure P10. This will be m2. You will use the motion detector to determine the acceleration of the system. In a physics lab, Kate and Rob use a hanging mass and pulley system to exert a 2. Peter Dourmashkin, Prof. ' and find. Work properly defined is the force along the direction of displacement multiplied by the magnitude of the displacement, s: Say that you use a rope to drag a gold ingot, and the rope is at an angle of 10 degrees from the ground instead of parallel. Apparatus: A wooden block, an inclined plane with pulley, cord, weights, a protractor, a balance, and. To find the tension in the rope, it's easiest to find equations for the forces accelerating the weights first. Calculate the force ratio for a pulley belt on a wheel when it is about to slip given the coefficient of friction is 0. 2 under bodies B and C. An engineer who wants to design a system so that it has a certain acceleration must be able to calculate the acceleration from the parameters defining the system. (b) Find the tension in the string and the acceleration of the 270-g block. Find Fujitec Friction Wheel Manufacturers & Suppliers from China. Atwood's machine is a common classroom demonstration used to illustrate principles of classical mechanics. A 13 kg block(mA) rests on a level table. If the system is accelerating at 3. Super Pulley attaches directly to the Smart Gate, providing a simple, low friction system to measure position, velocity and acceleration. Featuring dual Photogate beams, Laser switch, Photogate tape guide, and capability to daisy chain with either photogate or TIme-of-Flight accessory. Friction on pulley can be measured by compare theorhetical acceleration from force act and measure the actual acceleration to find the force done by friction. Physics 100A Homework 5 – Chapter 6. Physics 2101, First Exam, Fall 2007 September 4, 2007 Please turn OFF your cell phone and MP3 player! Write down your name and section number in the scantron form. As part a of the drawing shows, two blocks are connected by a rope that passes over a set of pulleys. Once block B is set into downward motion, it descends at a constant speed. 8 m/s2, mass of the pulley M = 1. Concepts: Interacting objects, Newton's laws. The Atwood's Machine is used below to help in understanding how Newton's 2nd law applies to a system of two connected masses. This force causes the ball to decelerate (that is, it has a "negative" acceleration). The coefficient of kinetic friction between the block and the table is. A smooth pulley is fixed at the vertex of the skeleton. A horizontal force Pis applied to the right on the block. Experiment 5 ~ Friction Purpose: In this lab, you will make some basic measurements of friction. A rotating mass stores energy. Coefficient of friction,. Find the acceleration experienced by each of the two objects shown in the ﬁgure if the coeﬃcient of kinetic friction between the 7. Worked example 8. The lightest is placed on the ground and the. Using graph paper, make a graph of the dependant variable vs. Find (a) The acceleration of the system (b) The tension in the cord! Solution. The Photogate/Pulley System uses a photogate head to monitor low-friction pulley rotation, providing a simple, versatile sensor. Can you figure out the acceleration of the cart -- which is the same as that of the weight -- in the presence of friction?. How to calculate tension in a multiple pulley system. That's the trick to quickly find the acceleration of some system that might be complicated if you had to do it in multiple equations and multiple unknowns but much, much easier once you realize this. Dynamics Exam1 and Problem Solutions 1. The pulley is a uniform disk of radius 8. The pulley shown above illustrates two forces, each exerting a torque on it. Find the acceleration and tension forces involved. While you are pulling, record the motion using the rotary motion sensor. 75 kg object which is released and allowed to fall, pulling the first mass after it. What is the acceleration of mass m2 on the inclined plane?. Adding a mass to the end of a rope does not cause the same acceleration as an equal applied force due to the inertia of the mass itself. Torque * rps > = Mass * Acceleration * Velocity / (2 * pi) Check out the user friendly RMF Calculator, or my outdated excel sheet for calculating RMF. The total mass is the sum of the two masses and the net force is the difference in the two weights. This example problem shows how to find the acceleration of an Atwood system and the tension in the connecting string. If the system is accelerating at 3. In other words you can find the mechanical advantage of a pulley system by applying a weight to the system and then determining the amount of. b) Find the magnitude of the tension in the string. I have a mass on a low friction track with a string connected over a pulley to a hanging mass. 2 used to calculate I. 4) Is there any friction at all and if so, how is it evident in your data?. 340-m radius, and is turning at 90. For the pulley system shown, each of the cables at A and B is given a velocity of 2 m/s in the direction of the arrow. That plot is shown in Figure 4, which displays a nice linear trend. A bucket with mass m 2 and a block with mass m 1 are hung on a pulley system. 5 kg mass slides down the ramp, and the suspended 7. Assume that the mass and friction of the pulley are negligible. A fixed (attached to a non-moving object) pulley changes the direction but not magnitude. A car in an amusement park ride rolls without friction around the track shown in the figure. We ignore the mass of the cord and pulley and any friction in the pulley, which means we can assume that a force applied to one end of the cord will have the same magnitude at the other end. •Assess the dependence of friction on the speed and mass load. 20, calculate the acceleration of each body and the tension T in the cable. 0-kg block resting on a frictionless horizontal ledge. ) Solution: The magnitude of the acceleration is a=2. 22 s, determine the coeﬃcient of kinetic friction between m 1 and the table. It is not a practical machine. The force due to friction is the sum of the tension in the strings on either side of the pulley. Draw each force with its tail at the surface of the system extending in the proper direction. Treat the car as a particle. (c) Indicate whether the magnitude of the acceleration of block 2 is now larger, smaller, or the same as in the original two-block system. 30 m/s2? If the rope on the right extends to the ground and is pulled by a co-worker, with what force magnitude must the co-worker pull for the man to rise c) with a constant velocity d) with an upward acceleration of 1. A string from 1 passes over a massless, frictionless pulley, and is attached to mass 2. Graph the acceleration versus the applied net force for cases having the same total mass. This force causes the ball to decelerate (that is, it has a "negative" acceleration). Let's say we have a system with a 10 kg weight (m 1) hanging vertically connected by a pulley to a 5 kg weight (m 2) on a 60 degree ramp (assume the ramp is frictionless). Assume that the mass and friction of the pulley are negligible. Now if the pulley is not frictionless (there is friction between the pulley and the cord), then the man must apply a greater force in order to support the box (because you are supporting the box and some of your force is dissipated due to friction) (the system here is also in equilibrium). Find the acceleration of the two block system in m/s2. 72 N, then what is the cart's acceleration?. 25m against the force exerted by the belt. Finding fK,BA, the magnitude of the friction force that A exerts on B, will be the simplest, since it has the same magnitude as fK,AB by virtue of the two being ThirdLawspouses. 00 kg bucket by a cord running over a frictionless pulley (Fig. Notice how acceleration of the system changes as you change these variables. To determine the influence of friction between the ramp and the package you run some tests. Find the acceleration of the system, in terms of g. 0 kg, determine the acceleration of the system. Course Links. You will then use these results to obtain g, the acceleration due to gravity. You can use it to calculate the pulley RPM (revolutions per minute), but also its diameter, and some properties of the whole system (such as the pulley speed, belt tension or torque). 1) Load the cart with a 100-g mass. 94 N , 11 0. The heavier weight has mass M1=5 kg and the lighter weight has mass M2= 2 kg. The coefficient of kinetic friction between box A and the table is 0. 0 kg mass hangs off the edge of the table. Acceleration due to Gravity. 600m/s2 is observed for block 2. What is the acceleration of the system?. The coefficient of friction between each box and the surface is uk = 0. asked by Toung on December 19, 2012; Physics. Find acceleration, tension & kinetic friction given mass and coefficient? A rectangular block of wood (block A) with a mass of 8 kg on the horizontal table is attached to a pulley. 05, mA = 2 kg and mB = 2 kg. nearly-frictionless inclined plane. Coefficient of friction,. The coefficient of friction between the object and the table is 0. Most pulley wheels have a central shaft on which they rotate. How to solve a system with Three blocks in a pulley system with kinetic friction constant given. cular to the ramp in order to find the acceleration of the cart along the ramp. Can you figure out the acceleration of the cart -- which is the same as that of the weight -- in the presence of friction?. Calculate the tension in the rope if the gymnast climbs up the rope with an upward acceleration of magnitude 1. The force due to friction is the sum of the tension in the strings on either side of the pulley. system = 32. provides the acceleration for an object in a circular motion: F c = ma = m v2 r e. The Newton's Second Law experiment provides the student a hands on demonstration of "forces in motion". Assume that the mass and friction of the pulley are negligible. 500kg , is connected over an ideal (massless and frictionless) pulley to block 2, of mass m2, as shown. A box is pulled with 20N force. Assume there is NO friction. 25, so that the tension (T) in both the strings is same. • This is an example of static equilibrium. Determine the acceleration of the book. Used to lift parallel loads, both lengths have the same amount of tension. Kinetic Friction Formula Questions: 1) A worker in a stock room pushes a large cardboard box across the floor. Set up the runway with a slope that you can adjust. Calculate the force caused by gravity on the basic pulley system using the following equation: G(1) = M(1) x n and G(2) = M(2) x n. The string is assumed to be light ( i. Assume the pulleys are massless and frictionless. The Atwood's Machine is used below to help in understanding how Newton's 2nd law applies to a system of two connected masses. there is no dissipation in the system, and the rope does not slide over the pulley. 8m above the ground.