Question

LEVEL -
4
A particle starts with an inital velocity 'u' and retardation. It reaches the initial position in a time
of
a)u/a
b)u/a square
c)u square/a
d)2u/a
of 1 ms​

Answer 1

Answer:

There is redundancy in the data given.

v = u + a t

=> 0 = u - a T substituting values

=> T = u/a

Distance covered before stopping: s = (v² - u²) / (2a)

=> s = (0- u²)/(-2a) = u²/ (2a)

time t to cover half total distance :

s = u t + 1/2 a t²

=> u²/(4a) = u t - 1/2 a t²

=> 2a² t² - 4 au t + u² = 0

=> t = [√2 + 1] u / (√2 a)

The time taken to cover 1st half is > the time taken to cover the second half distance. So we take + sign.

t = T * (√2 + 1)/√2

Answer 2

Check the attachment ☑......