Question

A car is moving with a uniform velocity 30 M per second it is stopped in 2 seconds by applying a force of 1500 Newton through its brakes calculate the change of momentum in car the retardation produced in car

Answer 1

Given :

Initial velocity , u = 30m/s

Force = 1500 N

Time , t = 2 sec

To find :

The change in momentum and the retardation in car .

Solution :

Using the first equation of motion ,

v = u - at

where , v is final velocity ,

minus sign for retardation .

putting the values ,

0 = 30 - a * 2

a = 15 m/$s^{2}$

now,

force = 1500 N

m * a = 1500 N

m = 100 kg

change in momentum of car = m ( v - u )

                                               = 100 (-30)

                                               = - 3000 kg m /s

The reatardation is 15m/$s^{2}$ and the change in momentum is - 3000 kg m /s .

Answer 2

Answer:Initial velocity , u = 30m/s

Force = 1500 N

Time , t = 2 sec

To find :

The change in momentum and the retardation in car .

Solution :

Using the first equation of motion ,

v = u - at

where , v is final velocity ,

minus sign for retardation .

putting the values ,

0 = 30 - a * 2

a = 15 m/

now,

force = 1500 N

m * a = 1500 N

m = 100 kg

change in momentum of car = m ( v - u )

= 100 (-30)

= - 3000 kg m /s

The reatardation is 15m/ and the change in momentum is - 3000 kg m /s .