 µ IB | Newton's Laws

10 quick questions

10 minutes maximum! (can you do it in 5?) Mr. Newton

1. Which of Newton's laws of motion states that "for every action there is an equal and opposite reaction"?

• A. Newton's First Law
• B. Newton's Second Law
• C. Newton's Third Law
• D. Newton's Fourth Law

2. Which of Newton's laws of motion states that "all objects will continue moving in a straight line at constant velocity unless acted on by a net force"?

• A. Newton's First Law
• B. Newton's Second Law
• C. Newton's Third Law
• D. Newton's Fourth Law

3. When an object is moving in a straight line at constant velocity, with no net forces acting, it is said to be in.....

• A. balance.
• B. translational equilibrium.
• C. stasis.
• D. vector equality.

4. Which of the following pairs of forces are 'Newton's third law pairs'?

• A. The force from a gun on a bullet, and the force causing the recoil of the gun.
• B. The force from a car's engine pushing it down a road, and the air resistance acting against the motion.
• C. The force from the Sun on the Earth, and the centripetal force pulling round in an orbit.
• D. The force produced by wind on a boat's sails, and the force of friction of the water on the boat.

5. This diagram shows a block sitting on the Earth's surface. The diagram is not to scale! There are 4 forces labelled. Which are Newton's third law pairs here?

 First Newton III pair Second Newton III Pair A W and Z R and Y B Y and Z R and W C R and Z W and Y D R and W Only one pair exists

6&7.One of Newton's Laws of motion refers to the rate of change of momentum, ΔP/Δt .

6. What is the rate of change of momentum equal to?

• A. Velocity
• B. Mass
• C. Acceleration
• D. Force

7. This law simplifies into a well known equation (for objects of constant mass). Which one?

• A. F = ma
• B. speed = distance ÷ time
• C. W = mg
• D. v = u + at

8-10. A school coach of mass 5000 kg accelerates from

2 ms-1 to 17 ms-1
over a 20 second interval. 8. What is the acceleration of the coach?

• A. 0.85 ms-2
• B. 34 ms-2
• C. 1.33 ms-2
• D. 0.75 ms-2

9. What is the change in momentum of the coach during this interval?

• A. 333 kg ms-1
• B. 85 000 kg ms-1
• C. 10 000 kg ms-1
• D. 75 000 kg ms-1

10. Assuming no friction or air resistance, what force was provided by the engine to provide this change in momentum?

• A. 0.25 kN
• B. 10.0 kN
• C. 3.75 kN
• D. 4.25 kN