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2 marksPower, P

CSEC Physics · 1990 · Paper 2 · Question 2(a)(i)

A car engine converts chemical energy to mechanical energy, with efficiency rarely exceeding 35%.

Give the formula for calculating the efficiency of the engine.

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Other parts of this question

  1. 2(a)(ii)A car uses gasolene of energy content 40 MJ per litre. If its engine is 30% efficient, how much useful work does it do for every litre of gasolene consumed?[2 marks]
  2. 2(a)(iii)The car travels at constant speed against an average retarding force of 1200 N. How far can the car travel on 1 litre of gas?[3 marks]
  3. 2(b)(i)State the principle on which the action of this machine is based.[2 marks]
  4. 2(b)(ii)Explain how the principle is applied to obtain a force great enough to support a car.[2 marks]
  5. 2(b)(iii)A force of 480 N is applied to piston A of area 0.01 m^2. What is the resulting pressure on the liquid?[2 marks]
  6. 2(b)(iv)What is the pressure on the large piston?[1 mark]
  7. 2(b)(v)What is the total force exerted on the large piston if its area is 0.15 m^2?[2 marks]

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