Question

If the engine of a car provides an acceleration of 2m/s 2 to start it from rest assuming the mass to be roughly 1000kg calculate force provides by the engine momentum after 10 sec time after which the car comes to rest if the engine is turned off after 15 sec [frictinal force=15N]

Answer 1

Velocity of car after 15sec:
V=u+at
here u=0, a=2m/s²,t=15sec
⇒0+2x15
⇒30m/s
V=30m/s
a=F/m
Force=15N
m=1000kg
⇒15/1000
0.015m/s²
Time taken to stop:
t=v-u/a
⇒0-30/-0.015
∵car engine is turned off, a  value will be negative.
⇒2000s

Answer 2

I ). From Newton's second law of motion forces is equal to mass cross acceleration. F is equal to M A is equal to 1000 x 2 is equal to 2000 Newton


ii ). Velocity after 10 second from first equation of motion V is equal to u plus at . V is equal to 20 metre per second

iii ). V is equal to 0 + 2 into 15 is equal to 30 metre per second. p is equal to Mv is equal to 1000 into 20 is equal to 20000 kg metre per second