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P4 General Studies: Forces and Simple Machines (Paper 2 (intermediate))
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P4 General Studies: Forces and Simple Machines (Paper 2 (intermediate))
Paper two adds power, wheels and axles, gears and efficiency, with three multi-step sums on ramps and pulley systems.
Direct answers Find the useful work first, then the input work, and only then the effort or the efficiency.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 |
| Suggested time | 20 |
| Difficulty mix | Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1 |
| Chapter | Chapter: P4 General Studies: Forces and Simple Machines |
| Level | parts of a closed circuit, conductors against insulators, series against parallel, adding up battery voltage, and electrical safety |
02 Questions (10 items)
- FoundationA 50 N box is carried horizontally for 10 m. How much work does the hand do on the box?
- FoundationA machine does 600 J of work in 20 s. What is its power?
- FoundationA 30 N load sits 0.4 m from the pivot and the effort is applied 0.6 m from it. What effort balances the lever?
- IntermediateA wheel and axle has a wheel radius of 30 cm and an axle radius of 10 cm. What effort lifts 270 N on the axle?
- IntermediateGear A has 20 teeth and drives gear B with 40 teeth. If A turns 60 times, how many turns does B make?
- IntermediateA 400 N crate needs 120 N to start sliding. What pull is needed for a 500 N crate of the same kind?
- ChallengeHow much work lifts a 2 kg object by 3 m, and what is the power if it takes 4 s?
- ChallengeA 400 N load is raised 1 m along a 4 m ramp with an efficiency of 80 per cent. What is the effort?
- ChallengeA movable pulley system with four rope sections lifts 800 N. What is the ideal effort and how far is the rope pulled to raise it 1 m?
- Error redoError clinic: the steeper the ramp, the less effort it saves. True?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | 0 J. | The upward force is perpendicular to the horizontal motion, so no work is done on the box. |
| 2 | 30 W. | Power is work over time, so 600 J over 20 s gives 30 W. |
| 3 | 20 N. | The load moment is 30 N times 0.4 m, that is 12 N m, divided by 0.6 m gives 20 N. |
| 4 | 90 N. | The arm ratio is 30 to 10, a force gain of three, so 270 over 3 gives 90 N. |
| 5 | 30 turns. | Twice the teeth means half the speed, so 60 times 20 over 40 gives 30 turns. |
| 6 | 150 N. | Friction grows with weight in the ratio 0.3, so 500 N times 0.3 gives 150 N. |
| 7 | 60 J, and 15 W. | The weight is 20 N, times 3 m gives 60 J, and 60 J over 4 s gives 15 W. |
| 8 | 125 N. | Useful work is 400 J, input work is 400 over 0.8 giving 500 J, and 500 J over 4 m gives 125 N. |
| 9 | 200 N, and the rope is pulled 4 m. | Four sections share the load, giving 200 N, and a force gain of four means four times the rope, that is 4 m. |
| 10 | No. | A steeper ramp covers less distance for the same height, so it saves less effort, and a vertical lift saves none. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
Then try paper three, using voltage and current to work out power and resistance.Tutor Registration →
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