# Finding displacement with acc and vel

1. Mar 17, 2015

### jebii

I'm working on a problem involving pulleys and would appreciate help. I know the initial starting positions of both objects (0.3 m above ground) and their initial velocity which is zero. The question wants me to find the maximum height the lighter object can achieve - i.e. its height even after the heavier object hits the ground, since it will be carried upwards by momentum. I have worked out the velocity of both objects, which are same magnitude and opposite directions, through equating kinetic energy and work done by gravity (since I know both their masses). I can also presume that, when the heavier object hits the ground, the lighter would have been lifted up by 0.3m, making it a total of 0.6m. I am just having problems with the additional height the lighter object travels through momentum, since I need to take into account the downward acceleration by gravity. (I am not given any information regarding time). Any advice on how to approach this would be appreciated.

2. Mar 17, 2015

### Simon Bridge

Hint: conservation of energy.