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1 markConservation of Energy

CAPE Physics Unit 1 · 2008 · Paper 2 · Question 4(a)(iii)

A body of mass, m, is moving in a circle of radius, r, with constant speed v.

Explain why the work done by the centripetal force on the mass is zero.

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Other parts of this question

  1. 4(a)A body of mass, m, is moving in a circle of radius, r, with constant speed v.[1 mark]
  2. 4(a)(i)Explain why there must be an acceleration experienced by the mass although it is moving at constant speed.[5 marks]
  3. 4(a)(ii)Write an expression for the magnitude of the acceleration and state the direction of this acceleration.[1 mark]
  4. 4(b)Figure 3 shows a pendulum with string of length 0.5 m and mass 1 kg being whirled at constant speed in a horizontal circle. The mass is 1.5 m above the ground.[1 mark]
  5. 4(b)(i)Draw the free body diagram showing the forces acting on the mass.[6 marks]
  6. 4(b)(ii)Calculate a) the tension in the string b) the speed of the mass.[1 mark]
  7. 4(c)During the motion the string suddenly breaks.[1 mark]
  8. 4(c)(i)Describe the subsequent motion of the mass.[4 marks]
  9. 4(c)(ii)Calculate the time it takes for the mass to hit the ground after the string breaks.[1 mark]

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