1.2. Motion
A subsection of Physics, 5054, through 1. Motion, forces and energy
Listing 10 of 196 questions
A ball rolls down a slope, as shown in . The metre rule shows the position of the ball at times t = 0, 1.0 s, 2.0 s and 3.0 s. cm slope ball metre rule t = 0 t = 1.0 s t = 2.0 s t = 3.0 s Explain how shows that the ball is accelerating. Calculate the average speed of the ball between t = 1.0 s and 3.0 s. average speed = Two of the forces that act on the ball are air resistance and weight. State what, if anything, happens to these forces as the ball accelerates. air resistance: weight: Explain why, if the slope is long enough, the ball eventually reaches a constant speed.
5054_s13_qp_22
THEORY
2013
Paper 2, Variant 2
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A children’s ride consists of a steel cable that runs between two posts of different heights, as shown in . steel cable post wheel A girl starts and finishes the ride at rest. Her horizontal motion can be taken as • an initial uniform acceleration for 3.0 s, followed by • a constant speed of 2.4 m / s for a further 5.0 s and • a final uniform deceleration that lasts for 1.0 s. On , draw a speed-time graph of the horizontal motion. time / s speed m / s Explain what is meant by uniform acceleration. The final deceleration is larger in size than the initial acceleration. Explain how the data shows this. Calculate the horizontal distance travelled by the girl in the first 8.0 s. distance = The girl has a mass of 30 kg and falls a vertical distance of 1.6 m during the ride. The gravitational field strength g is 10 N / kg. Calculate the decrease in gravitational potential energy of the girl. decrease in potential energy = The gain in kinetic energy of the girl is less than the decrease in her potential energy. Suggest one reason for this. A group of pupils make measurements to show that the girl’s speed is constant during the middle section of the ride. Suggest what measurements are made and how they show that the speed is constant.
5054_s14_qp_22
THEORY
2014
Paper 2, Variant 2
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shows a satellite in orbit around the Earth. Earth satellite (not to scale) The satellite travels at a constant speed in a circular orbit. Underline the quantities in the list below that are scalars. acceleration force mass speed velocity The velocity of the satellite changes, but its speed is constant. 1. State what is meant by velocity. 2. Explain why the velocity changes. Explain what makes this satellite move in an orbit that is circular. The satellite is placed into orbit by a rocket. shows the rocket as it takes off. thrust of engine resultant force weight The rocket and fuel have a total mass of 40 000 kg and a total weight of 400 000 N. The resultant force acting upwards on the rocket is 50 000 N. Calculate the thrust produced by the rocket engine. thrust = Calculate the acceleration of the rocket. acceleration = In the first four minutes after take-off, the acceleration of the rocket is uniform. State what is meant by a uniform acceleration. describes the motion of the rocket in the first 12 minutes. time / minutes motion of the rocket 0 to 4 uniform acceleration 4 to 6 increasing acceleration 6 to 10 decreasing acceleration 10 to 12 constant speed On , sketch the speed-time graph of the rocket for the first 12 minutes. You do not need to give values for the speed. speed time after take-off / min State how the speed-time graph in can be used to find the distance travelled by the rocket.
5054_s15_qp_21
THEORY
2015
Paper 2, Variant 1
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A bungee jumper falls from a bridge above a river, as shown in . position A at the top position B position C cord starts to stretch position D at the lowest point (not to scale) The man starts from position A in . The elastic cord starts to stretch at position C and he stops for the first time at position D. He continues to rise and fall. shows how the velocity of the man varies with time t. −20 −10 t / s velocity m / s −15 −5 State what is meant by velocity. State the difference between a positive velocity and a negative velocity. In the first 1.4 s the acceleration is uniform. 1. Using values from , determine the acceleration of the man in the first 1.4 s. acceleration = 2. Comment on your value of acceleration. 1. State the value of t when the man is at position D. 2. Explain, in terms of the forces acting, why the man is accelerating upwards at D. shows the values for the gravitational potential energy of the man, the kinetic energy of the man and the elastic potential energy in the cord at A, C and D. You may ignore the effect of air resistance in this question. gravitational potential energy / J kinetic energy / J elastic potential energy / J position A 20 000 position C 15 000 position D Complete to show the kinetic energy of the man at C and the elastic potential energy in the cord at D. The man has a mass of 50 kg. The gravitational field strength g is 10 N / kg. Using values from , calculate the vertical distance between A and C. distance =
5054_s15_qp_22
THEORY
2015
Paper 2, Variant 2
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A car accelerates from rest in a straight line. During the first 14 s, the acceleration is uniform and the car reaches a speed of 25 m / s. Calculate the acceleration of the car. acceleration = After the first 14 s, the speed of the car continues to increase but the acceleration decreases. From 70 s to 80 s after the start, the car moves at a constant speed of 55 m / s. On , draw a possible speed-time graph for the car. speed time / s m / s At a later time, the driver applies the brakes to stop. He is wearing a seat belt and slows down in his seat. A bag on the seat next to him slides forwards, across the seat towards the front of the car. Using ideas about the forces acting, explain why the driver slows down but the bag slides forwards.
5054_s17_qp_22
THEORY
2017
Paper 2, Variant 2
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Questions Discovered
196