Question

If a bullet loses 1/nth of its velocity while passing through a plank,then no of planks required to stop the bullet is?

Answer 1

mathematically....it just approaches zero but will never reach zero...it's like no matter how many times you take the half of numbers it will never become zero...

Answer 2

but the answer says n^2/2n-1

Answer 3

The energy loss per board is 1-((n-1)/n)^2 (Ke proportional to v^2)
No of boards is reciprocal of that which gives your answer above.

Answer 4

i still say it's mathematically approaching zero but never zero :p

Answer 5

Well try it with some number of boards...

Answer 6

Anyway, what is approaching zero? The velocity?
Obviously the bullet does stop at some point.