Question

A car of 900 kg mass is moving at the velocity of 60 km/hr. It is brought into rest at 50
metre distance by applying brake. Now, calculate the force required to stop the car.
3) A car of mass 500 kg is moving with a uniform velocity of 72 km/hr. What is the
momentum of the car?
4) A bus of mass 1000 kg is moving with the velocity of 90 km/hr. It stops suddenly by the
application of force of 600N. Calculate the time taken and distance travelled by the bus
when it is stopped.

Answer 1

Answer:

2)convert 60km/hr to m/sec=150/9 m/sec

v2-u2=2as

v2=0

u=150/9

s=50m

acceleration:=-2.7 m/sec2

f=ma

=900*2.7=-243N

the force should be applied on opposite direction

3)v=72×5/18=20m/sec

p=mv= 500*20=1000 kg m/sec

4)f=ma

a=600/1000=0.6m/sec2

u=25m/sec

v=u+at

here v=0m/sec

25/0.6=t

t=41.6 sec

s=ut+1/2at2

so find ...

hope so helpful..