InterviewSolution
Saved Bookmarks
| 1. |
s/Abullet travelling horizontally loses 1/20h of its velocitywhile piercing a wooden plank. Number of such planksrequired to stop the bullet is16 2193311 4 113 |
|
Answer» the bullet looses 1/20th of its velocity then V= 19/20u Since, v² = u² + 2as (19/20u)² = u² - 2as 2as = u² - (19/20u)² ................(1) Now, initial velocity = 0 Therefore 0² = u² - 2a (ns) u² = 2as (n) u² = n [ u² - 19²/20² u²] u² = nu² [ 20²-19²/20²] 20² = n [ 20² - 19² ] 20² = n [ (20+19)(20-19) ] n = 400/39 n ~ 11 planks |
|