Mass times velocity defines momentum and its unit is kg m/s, so this Year 12 sheet opens with the definition and its unit. The answers add Ft = Δp for impulse and note that in an inelastic collision kinetic energy is not conserved but momentum is.
Key Takeaways
Momentum is mass × velocity (Q1).
The unit of momentum is kg m/s (Q2).
Q5 records Ft = Δp as the impulse equation.
Section A: Multiple Choice Questions (1 Mark Each)
Choose the correct option for each question.
1.Momentum is defined as
(a) mass × velocity(b) mass × acceleration(c) force × distance(d) mass × displacement
2.The unit of momentum is
(a) kg m/s(b) newton(c) joule(d) N/m
3.Momentum is conserved in a collision provided that
(a) no external force acts on the system(b) the collision is elastic(c) the objects are heavy(d) only one object moves
4.Impulse is equal to
(a) the change in momentum(b) the change in speed(c) force × distance(d) the work done
5.The impulse–momentum principle is written as
(a) Ft = Δp(b) F = Δp ÷ t(c) Ft = m(d) Ft = v
6.In an inelastic collision
(a) kinetic energy is not conserved but momentum is(b) both momentum and kinetic energy are conserved(c) nothing is conserved(d) only kinetic energy is conserved
Section B: Short Answer Type Questions (2 Marks Each)
Show all steps clearly.
7.Define momentum and state its unit.
8.State the principle of conservation of momentum.
9.Define impulse.
10.Write the impulse–momentum equation.
11.What is the difference between elastic and inelastic collisions?
12.Why do seat belts reduce the force acting on a driver during a crash?
13.What is a perfectly inelastic collision?
14.A force acts on an object for 2 s. How is the impulse calculated?
Section C: Numericals & Word Problems (3 Marks Each)
Apply the concepts to solve the problems. Show all working.
15.A 2 kg ball moves at 5 m/s. Using p = mv, find its momentum.
16.A force of 10 N acts on an object for 3 s. Using impulse = Ft, find the impulse.
17.A 5 kg object moving at 4 m/s is stopped in 0.2 s. Using F = Δp ÷ t, find the average force.
18.A 2 kg trolley moving at 3 m/s hits and sticks to a 1 kg trolley that is at rest. Using conservation of momentum, find the combined velocity.
19.A car of mass 1000 kg changes its velocity from 10 m/s to 20 m/s. Find the change in momentum.
20.An impulse of 20 Ns changes the velocity of a 4 kg object. Using Δv = impulse ÷ mass, find the change in velocity.
Answer Key
1. a) mass × velocity
2. a) kg m/s
3. a) no external force acts on the system
4. a) the change in momentum
5. a) Ft = Δp
6. a) kinetic energy is not conserved but momentum is
7. Refer to solution guide.
8. Refer to solution guide.
9. Refer to solution guide.
10. Refer to solution guide.
11. Refer to solution guide.
12. Refer to solution guide.
13. Refer to solution guide.
14. Refer to solution guide.
15. Refer to solution guide.
16. Refer to solution guide.
17. Refer to solution guide.
18. Refer to solution guide.
19. Refer to solution guide.
20. Refer to solution guide.
End of Worksheet
People Also Ask
What is momentum?
Mass × velocity, option (a) in this worksheet (Q1).
What is the unit of momentum?
kg m/s, option (a) in this worksheet (Q2).
What is impulse equal to?
The change in momentum — Ft = Δp, option (a) in this worksheet (Q5).
Stuck on a similar problem? Clear your next doubt instantly with the Doubt Solver.
Browse more free worksheets for A Level Year 12.