GYSS 4E Prelim Physics P2_Question

2 Section A (70 marks) Answer all the questions in the spaces provided. 1 The diagram shows a model car with a mass of 0.25 kg. The car is travelling at a constant speed of 1.70 m/s as it approaches the rough ramp. The average friction opposing the motion of the car down the ramp is 0.15 N. Assume air resistance is negligible. (a) Calculate the work done against friction as it moves down the rough ramp. work done against friction = ………………………… [1] (b) Calculate (i) the loss in gravitational potential energy as the car moves down the ramp, loss of gravitational potential energy = ………………………… [1] (ii) the speed of the car at the bottom of the rough ramp. speed of the car = ……………………………… [2] 0.80 m 0.42 m

3 (c) Draw a free body diagram of the car moving down the ramp, labelling the forces acting on the car. [2] [Total: 6] 2 Fig. 2.1 shows a lorry accelerating along a straight road. The driving force exerted on the lorry in the forward direction is D and the total backward force acting on the lorry is B. Fig. 2.1 The gravitational field strength is 10 N/kg. (a) Compare the magnitude of the forces D and B. Give a reason for your answer. ……………………………………………………………………………………………… ……………………………………………………………………………………...……[1] (b) The lorry subsequently turns a corner at a constant speed of 12 m/s. (i) Express the speed of the lorry in km/h. speed = …………………………[1]

4 (ii) State and explain whether the lorry is accelerating when it turns the corner. ……………………………………………………………………………… …………………………………………………………………...………[1] [Total: 3] 3 Fig. 3.1 shows a uniform plank of mass 5.0 kg and length 2.0 m resting horizontally on two trestles, P and Q. Fig. 3.1 Trestle Q exerts a force of 440 N on the plank when an object of mass 65.0 kg is placed at a distance, d, from P. The gravitational field strength, g = 10 N/kg. (a) Calculate the moment due to the weight of the plank. moment due to weight of plank = ……………………………..[1] (b) Define principle of moment. ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………...……[1] P Q d 65 kg

5 (c) Determine the distance d, of the object from P. d = …………………………….[2] [Total: 4] 4 (a) Fig. 4.1 shows a ray of light XY being directed at the surface AB of an irregular- shaped glass block ABCDE. Fig. 4.1 (i) Explain why the ray XY enters surface AB without bending. …………………………………………………………………………………..[1] (ii) Determine the critical angle of the glass. critical angle = ...........................