Question

if a bus travelling at 20m/s is subjected to a steady deceleration of 5m/S square 2,how long will it take to come to rest

Answer 1

Hi , there !!!

u = 20 .


v = 0


a = 5m / s² .


v² - u² = 2as .

-400 = 2 × 5 × s


=> 40 m .


hence , it will take 40m to come in rest .


hope it helps you !!!

thanks !!

Ranjan kumar

Answer 2

given :-

u (Initial velocity) = 20m/s

acceleration = -5m/s²

v (final velocity) = 0m/s

by using 3rd equation of motion we get

==> 2as = v² - u²

==> 2(-5)(s) = 0² - 20²

==> -10s = -400

==> s = -400/-10

==> s = 40m

the distance travelled by the bus is 40m.

now we have to find the time taken by bus to travel 40m.

we know that a = (v - u)/t

therefore at = v - u

==> -5t = 0 - 20

==> -5t = -20

==> t = -20/-5

==> t = 4 seconds

HOPE THIS HELPS..!!