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Physics Grade 9 Unit 4: Force, Work, Energy and Power
national exam questions have come from this unit. It runs 22 pages; one careful study pass takes about 2.0 hours, and its difficulty is easier among Physics units. Each section below lists the questions set from it, with the year, and opens the page that teaches it.
4.1 The Concept of Force · read p. 64
Not asked in a national paper yet.
4.2 Newton’s Laws of Motion · read p. 66
- 2017 E.C., Q14 – According to Newton's first law, an object that is in motion continues its state of motion with
- 2010 E.C., Q17 – An object of mass 1kg moving with a speed of 2m/s was acted on by a force that produces an acceleration of 2 m/s2 . What is the change in kinetic energy of the object if the force is exerted on the object for 2seconds in
4.3 Forces of Friction · read p. 73
Not asked in a national paper yet.
4.4 The Concept of Work · read p. 74
Not asked in a national paper yet.
4.5 Kinetic and Potential Energies · read p. 76
- 2017 E.C., Q59 – A crane at port is used to lift a 10,000 kg object to a height of 20 m. If the power developed by the crane is g = 10m/s2 50,000 W, how long does it take to lift the object? (Acceleration due to gravity, )
- 2013 E.C., Q48 – A 5.0 kg stone is dropped from a top of 30.0 m building. At a height of 10.0 m above the ground, 60% of its initial potential energy is converted to kinetic energy. Which of the following statements is correct about the
- 2005 E.C., Q4 – One person drops a ball from the top of a building while another person at the bottom observes its motion. The two people disagree on which of the following?
4.6 Power · read p. 80
Not asked in a national paper yet.