Question

a body of mass m is slowed down from velocity 30m/s to rest in 2secs. calculate the force needed to apply?​

Answer 1

Answer:

-15m N

Explanation:

Change in acceleration in 2 sec (deceleration) is :

(v - u) / t = a

(0 - 30)/2 = a

a = -15m/s

Force applied is m.a = m(-15) Newtons  

Answer 2

u=30m/s

v=0m/s

time =2 sec

acceleration =(v-u)/t

=(0-30)/2

=-15m/s^2

so force required=ma

=m *-15

=-15m N