Question

A driver applies the brakes on seeing traffic singal 400m ahead. At the time of applying of brakes vehicle was moving with speed `15 m//s`. The brekes provide uniform deceleration of `0.3m//s^(2)`. The displacement of the vehicle in 1 mmin duration after the driver sees the singal is :
A. `25m`
B. `375m`
C. `360m`
D. `40m`

Answer 1

Correct Answer - B
A driver ………..
The vehicle suffers displacement only till it stops and not of afterwards as brakes provide acceleration till `v != 0`
`:.` for displacement
`Delta x, v_(x)^(2) = u_(x)^(2)+2a_(x)Delta x`
`v_(x)= 0 implies Delta x = ((15)^(2))/(2xx0.3)= 375 m`