4.1.6 Momentum

Question 1

State the equation & units for momentum.

Answer 1

→ momentum = mass x velocity
→ measured in kilograms metres per second

Question 2

State what is meant by the conservation of linear momentum.

Answer 2

total momentum before = total momentum after

Question 3

Define force in terms of momentum and time. State the equation.

Answer 3

→ the rate of change of momentum
→ force = Δmomentum/time

Question 4

State the equation for force in terms of mass and velocity.

Answer 4

force = Δ(mv)/t

Question 5

What is impulse?

Answer 5

impulse = change in momentum

Question 6

State the equation for impulse.

Answer 6

Δp = f x Δt

Question 7

What does the area under a force-time graph represent?

Answer 7

change in momentum

Question 8

What is the relation between impact time and impact force?

Answer 8

→ if impact time increases, impact force will decrease
→ if impact time decreases, impact force will increase
→ (inversely proportional)

Question 9

What happens in an elastic collision?

Answer 9

→ momentum is conserved
→ kinetic energy is conserved
→ total energy is conserved

Question 10

What happens in an inelastic collision?

Answer 10

→ momentum is conserved
→ kinetic energy is not conserved but transferred to other energy stores
→ total energy is conserved

Question 11

What is the relationship between momentum and kinetic energy?

Answer 11

P = mv & KE = 1/2mv2
v = √2mE so P = m √2mE
therefore P is proportional to square root of E