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5. Work, energy and power
A section of Physics, 9702
Listing 10 of 242 questions
A ball is thrown from A to B as shown in . 60° V A B The ball is thrown with an initial velocity V at 60° to the horizontal. The variation with time t of the vertical component Vv of the velocity of the ball from t = 0 to t = 0.60 s is shown in . –6.0 –4.0 –2.0 2.0 4.0 6.0 t / s velocity / m s–1 0.2 0.4 0.6 0.8 1.0 1.2 1.4 Vv Assume air resistance is negligible. Complete for the time until the ball reaches B. Calculate the maximum height reached by the ball. height = m Calculate the horizontal component Vh of the velocity of the ball at time t = 0. Vh = m s−1 On , sketch the variation with t of Vh. Label this sketch Vh. The ball has mass 0.65 kg. Calculate, for the ball, the maximum kinetic energy, maximum kinetic energy = J the maximum potential energy above the ground. maximum potential energy = J
9702_w14_qp_22
THEORY
2014
Paper 2, Variant 2
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An object is moved from point P to point R either by a direct path or by the path P to Q to R, as shown in . horizontal vertical R Q P object P and Q are on the same horizontal level. R is vertically above Q. Explain whether the work done moving the object against the gravitational field is the same or different along paths PR and PQR. A ball is thrown with an initial velocity V at an angle θ to the horizontal, as shown in . e path of ball horizontal V (not to scale) The variation with time t of the height h of the ball is shown in . 2.0 4.0 6.0 8.0 10.0 h / m t / s 12.0 1.00 2.00 3.00 Air resistance is negligible. Use the time to reach maximum height to determine the vertical component Vv of the velocity of the ball for time t = 0. Vv = m s–1 The horizontal displacement of the ball at t = 3.00 s is 25.5 m. On , draw the variation with t of the horizontal displacement x of the ball. x / m t / s 1.00 2.00 3.00 For the ball at maximum height, calculate the ratio potential energy of the ball kinetic energy of the ball . ratio = In practice, air resistance is not negligible. State and explain the effect of air resistance on the time taken for the ball to reach maximum height.
9702_w15_qp_21
THEORY
2015
Paper 2, Variant 1
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An 8.00 N weight is attached to the lower end of a spring which is fixed at its upper end. The weight is initially held at rest at position X and the spring is unstretched. The weight is then released and falls to position Y, which is 4.00 cm below X. The weight oscillates and then eventually comes to rest at O, which is 2.00 cm below X. X 8.00 N spring unstretched Y 8.00 N position after initial drop O 8.00 N 2.00 cm final position after many oscillations 4.00 cm How much energy is lost from the system?
9702_w18_qp_11
MCQ
2018
Paper 1, Variant 1
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Questions Discovered
242