Question

Calculate the change in momentum of a car of mass 1000kg when its speed increase from 36km h-¹ to 108km h-¹ uniformly

Answer 1

m = 1000 kg
v1 = 36 km/h = 10 m/s
v2 = 108 km/h = 30 m/s
p1 = 1000×10
    = 10000 kg m/s
p2 = 1000×30
    = 30000 kg m/s
Change = (30000-10000) kg m/s
20000 kg m/s
The change will be occur in Car direction where it was going before change.

Answer 2

Given,

m = 1000 kg 

Velocity v1 = 36km/h = 36 * 5/18 = 10 m/s

Velocity v2 = 108km/h = 108 * 5/18 = 30 m/s

formula for momentum is p = m2v2 - m1v1

                                              = 1000 * 30 - 1000 * 10

                                              = 30000 - 10000
                                 
                                              = 20000