Question

A motorcar of mass 1200kg is moving a straight line at a velocity of 90km/h its velocity is decrease to 18km/h in 4 sec by applying unbalanced force. calculate the acceleration, change in momentum and magnitude of the force required

Answer 1

hope it help you I tried my bast

Answer 2

Given :

mass = 1,200 kg .

initial velocity = 90 km/hr

             = 90 × 5/18 m/s

             = 5 ×5 m/s

             = 25 m/s

final velocity = 18 km/hr

                     = 18 × 5/18 m/s

                     = 5 m/s

Acceleration

a = ( v - u ) / t

= > a = ( 25 - 5 ) / 4

= > a = 20 / 4

= > a = 5 m/s²

Change in momentum = m ( v - u )

                                     = 1200 kg ( 25 - 5) m/s

                                     = 1200 kg × 20 m/s

                                = 24,000 kg m/s

Force

Force = mass × acceleration

          = 1200 kg × 5 m/s²

          = 6,000 N

The force is 6,000 N