Question

a vehicle of mass 120kg is moving with a velocity of 90km/h. what force should be applied on the vehicle to stop it in 5 secs?

Answer 1

90km/hr=25m/s
v=u+at
0=25+5a
a=5m/s^2
force is ma
=120×5
=600N

Answer 2

Answer:

u=90kmph, 25m/s (90×5/18)

v=0m/s

t=5 seconds

a=v-u

t

=0-25/5

a =-5 ms^-2

m=120kg

f=ma

= 120×-5

= -600 N

therefore magnitude of force is 600N