Physics Past Paper Qs PDF

## Q1. The figure below shows a person using a zip wire to move from a tree to the ground. **Image:** A diagram of a person on a zip wire. The zip wire is attached to a pulley at the top of a tree, and the person is holding the zip wire and is moving down. There is a trolley with wheels on the zip...

## Q1. The figure below shows a person using a zip wire to move from a tree to the ground. **Image:** A diagram of a person on a zip wire. The zip wire is attached to a pulley at the top of a tree, and the person is holding the zip wire and is moving down. There is a trolley with wheels on the zip wire, and a block is attached to the trolley by a rope. The rope goes over the pulley. As the person moves down the zip wire, the block moves upwards. **(a)** What happens to the gravitational potential energy of the person as the person accelerates down the zip wire? Tick (✔) one box. - Decreases - **Stays the same** - Increases **(b)** What happens to the kinetic energy of the person as the person accelerates down the zip wire? Tick (✔) one box. - **Increases** - Decreases - Stays the same **(c)** The block is 3.4 m above the ground when the person is at the bottom of the zip wire. Mass of block = 2.5 kg Gravitational field strength = 9.8 N/Kg Calculate the gravitational potential energy of the block. Use the equation: Gravitational potential energy = mass × gravitational field strength × height Gravitational potential energy = 83.3 J **(d)** The trolley is a seat suspended from wheels which can roll along the zip wire. When the person reaches the end of the zip wire, the person gets off the trolley. The block falls downwards pulling the trolley back to the top of the zip wire. Maximum speed of block = 4.8 m/s Mass of block = 2.5 kg Calculate the maximum kinetic energy of the block. Use the equation: Kinetic energy = 0.5 × mass × (speed)² Maximum kinetic energy = 28.8 J **(e)** As the trolley moves, work is done against friction. What is the effect of this? Tick (✔) one box. - Some energy is destroyed. - **Some energy is transferred to the surroundings.** - The total energy of the block and trolley increases. **(f)** The person oils the wheels on the trolley. Explain how this will affect the speed of the person down the zip wire. There is no friction against the zip wire so it will go faster as no friction is produced. ## Q2. A trampoline is made from a sheet of material help in place by stretched springs. **Image:** A child is standing on a trampoline which is curved downwards. The trampoline is held in place by stretched springs on the sides. **(a)** Position A shows the child's maximum height above the trampoline. Position B shows the lowest position reached by the child when landing on the trampoline. Describe the changes to the stores of energy of the: - Child - Springs - Surroundings As the child moves from position A to position B. The GPE of the kid when he is at the maximum height the GPE increases, and while landing back the springs stretch and elastic energy is happening and that makes a noise like a boing which goes to the surroundings and gets dissipated. **(b)** When the child is at position A, each trampoline spring is stretched by 0.056 m. The elastic potential energy of each spring is 4.9 J. When the child is at position B, the elastic potential energy of each spring increases to 8.1 J. Calculate the extension of each spring when the child is at position B. Use the Physics Equations Sheet. Extension = 0.072 m **(c)** As the child bounces on the trampoline, the child does work. What is the work done by the child equal to? Tick (✔) one box. - The average force applied by the child - The maximum force applied by the child - **The total energy transferred by the child** - The total energy store of the child ## Q3. Figure 1 shows a child's toy. **Image:** A toy that is a spring on top of a small, smiling bug. The toy has a bug on top of the spring. There is a smaller bug at the bottom, and a bigger bug on top. When the small bug is pressed down on the bigger bug, the spring compresses and launches the bigger bug upwards. A child pushes down on the toy to compress the spring. The spring then launches the toy into the air. **(a)** A student measured the maximum height reached by the toy. The student placed a vertical metre rule near the toy and observed the height reached by the toy. The student repeated the experiment, observing from a different position. Figure 2 shows the toy at its maximum height and the two positions of the student. **Image:** Two images of the toy at maximum height, seen by a student from two different positions. The student is holding a ruler. In the first image, the student is standing further away from the toy, and in the second image, the student is standing closer to the toy. Observing the toy from position B instead of position A affected the measurement of the maximum height reached by the toy. Explain how. The measurement will be more accurate because (in position B) the eye is level with (the maximum height of the toy) **(b)** The greatest height reached by the toy was 64 cm. The gravitational potential energy of the toy at this height was 0.049 J. Gravitational field strength = 9.8 N/Kg Calculate the mass of the toy. Use the Physics Equation Sheet. Give your answer to 2 significant figures. Mass of toy (2 significant figures) = 0.0078 kg **(c)** When the spring launches the toy into the air, the temperature of the air increases. Explain why the child's toy, on its own, is not a closed system. Energy from the toy is dissipated (to the surroundings/air). ## Q4. The figure below shows a device that uses a mug of hot coffee to turn a wheel. **Image:** A mug of hot coffee placed on a device with a piston and air chamber. The air chamber is connected to a wheel via a pipe. **(a)** The hot coffee increases the temperature of the air in the chamber. Explain how the pressure in the chamber changes. (Air) particles move faster or (air) particles have increased kinetic energy. (So air) particles collide more frequently with the wall/chamber or (so air) particles collide with more force with the wall/chamber . (So) the pressure increases. **(b)** For the device to work, the air in the chamber must increase in the temperature quickly. Explain why the bottom of the air chamber is made of metal rather than plastic. (Metals) have a high(er) thermal conductivity which allows a greater rate of (thermal) transfer or allows (thermal) energy is transferred more quickly. **(c)** The mass of air in the chamber is constant. What property off air allows a small change in internal energy to cause a large temperature change to the air in the chamber? (A low) specific heat capacity. **(d)** The changes in pressure in the air chamber cause the wheel to turn. Suggest *one* way to increase the speed at which the wheel turns. Any one from: lubrication; use hotter coffee; decrease the temperature of the surroundings. **(e)** The temperature of the coffee decreases as the device is used. The initial temperature of the coffee was 76 °C. The internal energy of the coffee decreased by 15 kJ Density of coffee = 1.1 x 10³ kg/m³ Volume of coffee = 1.9 x 10^-4 m³ Specific heat capacity of coffee = 4200 J/Kg °C Calculate the final temperature of the coffee. Use the Physics Equations Sheet. Final temperature of the coffee = 59°C.