These eight questions go from converting units to explaining inertia. Write each answer on paper before opening the explanation.
The set covers force and motion. The timed practice session builder can run it against a clock.
Questions
Question 1 (1 mark). Convert 72 km/h to m/s. (Hint: divide by 3.6.)
Answer
72 ÷ 3.6 = 20 m/s.
Question 2 (2 marks). An invented runner covers 400 m in 80 s at a steady pace. Calculate the speed.
Answer
Speed = 400 ÷ 80 = 5 m/s.
Question 3 (2 marks). A car increases its velocity from 4 m/s to 16 m/s in 3 s. Calculate its acceleration.
Answer
Acceleration = (16 − 4) ÷ 3 = 12 ÷ 3 = 4 m/s².
Question 4 (2 marks). A distance-time graph shows a straight line from 0 m at 0 s to 30 m at 6 s. State the speed and what a flat line at a later time would mean.
Answer
Speed = slope = 30 ÷ 6 = 5 m/s. A flat line would mean the object is not moving.
Question 5 (3 marks). A velocity-time graph for an invented cart rises from 0 to 8 m/s in 4 s, then stays at 8 m/s for 5 s. Find the total distance.
Answer
Stage 1 area: ½ × 4 × 8 = 16 m. Stage 2 area: 8 × 5 = 40 m. Total = 16 + 40 = 56 m.
Question 6 (2 marks). A 600 g toy car accelerates at 2.5 m/s². Calculate the resultant force.
Answer
Convert the mass: 600 g = 0.6 kg. F = 0.6 × 2.5 = 1.5 N.
Using 600 directly would give 1 500 N, the usual gram error.
Question 7 (3 marks). A 3 kg trolley at 4 m/s hits a stationary 1 kg trolley and they stick together. Find their velocity after the collision.
Answer
Momentum before = 3 × 4 = 12 kg m/s. After: combined mass 4 kg, so 4v = 12 and v = 3 m/s.
Question 8 (3 marks). A bus brakes suddenly and a standing passenger lurches forward. Explain using inertia.
Answer
Before braking the passenger moved forward with the bus. The bus slowed, but no force acted to slow the passenger’s body at the same moment. Because of inertia, the body continued moving forward.
Do not write “the force of inertia”. Inertia is a property, not a force.
If you got these wrong
Missed 1 to 3: revisit calculating speed, velocity and acceleration. Missed 4 and 5: go to reading motion graphs.
Missed 6 and 7: read applying force and momentum relationships. Missed 8: see explaining inertia using safe thought experiments.
Log each error in the mistake log and paper-error review. If you want a teacher to go through your working line by line, see online one-to-one Science tuition.