InterviewSolution
Saved Bookmarks
| 1. |
8. A ball dropped from a balloon at rest cltower 81 m high during the lastof its journey. Find the height of the alldand the velocity of the body when itthe ground.quarter secoreacheAns 2684.2 m 324 30 |
|
Answer» The last quarter of the jouney means 1/4th of the total time it requires in its total journey. Let total time be 4t, u = 0. So, v at 3t = 3gt, and at 4t = 4gt. by v² = u² + 2as, 16g²t² = 9g²t² + 2g(81) 7g²t² = 162g 7gt2= 162 t² = 162 / 7g t = 1.5 sec. but time is 4t = 6 sec. So velocity on reaching = 4gt =58.8 m/s With this velocity, height of fall = 2t(58.8) =705.6m |
|