Thread: Atwood

Need to find the distance for this problem. I found acceleration and tension.Can someone work this out step by step.

two objects with masses of 9.76kg and 4.81kg hang 2m from the floor from the ends of a cord 8.0m long passing over a frictionless pulley. Both objects are released from rest. What is the maximum height above the floor reached by the 4.81kg object.


Thanks in advance

Originally Posted by john haas

Need to find the distance for this problem. I found acceleration and tension.Can someone work this out step by step.

two objects with masses of 9.76kg and 4.81kg hang 2m from the floor from the ends of a cord 8.0m long passing over a frictionless pulley. Both objects are released from rest. What is the maximum height above the floor reached by the 4.81kg object.


Thanks in advance

4m. Think about it .....

nvm i get it since i think 4.81 is less than half the mass of the original it won't have an affect right?

I thought when the heavier object traveled down 2m that the light object would go up 2m+2m and then it would travel a little more to de-accelerate.



Thank you for your time.

Originally Posted by john haas

I thought when the heavier object traveled down 2m that the light object would go up 2m+2m and then it would travel a little more to de-accelerate.



Thank you for your time.

Sorry, I misunderstood the question. I thought you meant equilibrium height.

You need to calculate the speed the lighter object is moving at when it's a height of 4 m above the ground, that is, after travelling 2m. Call that that speed the initial speed u. At this height the string is slack and the acceleration of the light obejct is due to gravity: a = - 9.8 m/s^2. At the top of its path the final velocity is 0: v = 0. You need to calculate the distance x and add it to the 4m.

u = .....
v = 0
a = -9.8 m/s^2
x = ?