Momentum and Force

 

 

The momentum of a body is the product of its Mass and Velocity

 

Momentum = Mass x Velocity

 

Units: kgm/s = kg x m/s

 

 

 

Calculate the momentum of the following

 

1. A sprinter of mass 80 kg running at 9 m/s

 

2. A marathon runner of mass 70 kg running at 4.2 m/s

 

3. A car of mass 90 kg travelling at 25 m/s

 

4. An aircraft of mass 19000 kg travelling at 555 m/s

 

5. A falcon of mass 550 g diving at 90 m/s

 

 

 

When the momentum of a body changes an overall (resultant) force acts on the body

 

 

 

F = final momentum initial momentum = mv - mu

Time taken t

 

 

 

Calculate the resultant force:

 

1. A car of mass 500 kg travelling at 40 m/s is brought to rest in 5 s in 0.2 s

 

2. A tennis ball of mass 57 g is hit from rest to a speed of 15 m/s in 0.2 s

 

3. A cricket ball of mass 130 g is brought to rest from a speed of 16 m/s

 

4. A car of mass 500 kg reaches a speed of 45 m/s from rest in 5.7 s