Momentum

Question 1

Change in momentum

Answer 1

The rate of change of momentum of a body is directly proportional to the resultant force applied to the body, and is in the same direction as the force

Question 2

Change in momentum equation

Answer 2

Change in momentum (kg m/s) = force x time

Question 3

Explain why a cricket player brings his hands to his chest when catching a ball?

Answer 3

• Time the force is applied momentum increases
• Rate of change in momentum decreases
• This reduces the force on his hand

Question 4

Conservation of linear momentum

Answer 4

Total momentum before collision = Total momentum after collision

Question 5

The law of conservation of linear momentum states that:

Answer 5

The momentum of a system will remain constant, unless an external force acts.

Question 6

law of conservation of linear momentum equation

Answer 6

m1u1 + m2u2 = m1v1 + m2v2

Question 7

Explosions

Answer 7

• The total momentum of a stationary object is zero
• If it then explodes, the total momentum (of the various parts) remains zero
• The total momentum of the object is conserved

Question 8

Elastic collision

Answer 8

A collision in which both momentum and kinetic energy are conserved

Question 9

Inelastic collision

Answer 9

A collision in which momentum is conserved and kinetic energy isn’t conserved

Question 10

Explain the purpose of a cars crumple zone

Answer 10

• Increases time of collision
• Decreases the rate of change of momentum
• Decreases the force on the passengers