Question

a car is moving with a uniform velocity of 30m/s It's stopped in 2s by applying a force of1500N through its brakes.calculate:
1)the retardiation produced in car
2)the mass of car,and
3)the change in momentum
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Answer 1

Answer:

This is the answer.

Answer 2

Step-by-step explanation:

Given,u=30m/s

v=0

t=2s

F=1500N

1)a=?

By 1st law of motion,

v=u+at

a=v-u/t

a=0-30/2

a= -15m/s^2

2)F=ma(second law of motion)

m=F/a

m=1500/-15

m= -100kg but mass cannot be negative... therefore,m=100kg

3)change in momentum=pfinal-pinitial

pinitial=mu=100×30=3000Kgm/s

pfinal=mv=100×0=0Kgm/s

change=mv-mu=0-3000= -3000Kgm/s