# Change in Kinetic Energy

by Manula
Tags: energy, kinetic
 P: 29 There is a uniform log lying on the ground.Now we can lift this up from one end such that the other end is in contact with the ground.Now keep the log vertical. Case 1: Let the log fall freely such that when it comes to rest it is inline with the initial position of the log. Case 2: Let the log fall freely such that it makes angle(say 60°) with the initial position when it comes to rest. My question is, in the two cases the distance between the center of masses of the log in its initial position and final is different, Even though the cases are similar. What causes this difference?
HW Helper
Thanks
PF Gold
P: 26,105
Hi Manula!
 Quote by Manula … in the two cases the distance between the center of masses of the log in its initial position and final is different, Even though the cases are similar. What causes this difference?
There's no difference in kinetic energy

they both end up with zero KE (and they both had mgh KE just before they hit the ground) …
we don't need any energy to move something from one stationary position to another!
 P: 29 tiny-tim, Thank you!! :)

 Related Discussions Introductory Physics Homework 5 Introductory Physics Homework 0 Introductory Physics Homework 10 Introductory Physics Homework 9 Introductory Physics Homework 1