5054_w20_qp_22
A paper of Physics, 5054
Questions:
9
Year:
2020
Paper:
2
Variant:
2
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1
A glass beaker has a mass of 50 g. A liquid of density 1.8 g / cm3 is poured into the beaker until it reaches the 200 cm3 mark. Calculate the total mass of the beaker and its contents. mass = The centre of mass of a metre rule is at the 50 cm mark. State what is meant by centre of mass. The metre rule is placed on a pivot. The tip of the pivot is under the 80 cm mark on the rule. The beaker with its contents is then placed at different positions along the rule until the rule is balanced. shows the arrangement with the rule balanced. beaker 92 cm mark 84 cm mark 80 cm mark 50 cm mark metre rule centre of mass of rule pivot One side of the beaker is at the 84 cm mark and the other side is at the 92 cm mark. Calculate the mass of the rule. mass =
1. Motion, forces and energy  →  1.5.6. Centre of gravity
1. Motion, forces and energy  →  1.3. Mass and weight
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2
The total mass of a wheelbarrow and its load is 90 kg. A worker pushes the wheelbarrow and load up a plank of length 2.0 m on to a platform, as shown in . The platform is at a height of 0.60 m above the ground. 0.60 m platform load 290 N 2.0 m The worker exerts a force of 290 N on the wheelbarrow in the direction in which the wheelbarrow moves. The gravitational field strength g is equal to 10 N / kg. Calculate the gravitational potential energy gained by the wheelbarrow and its load. energy = The worker pushes the wheelbarrow 2.0 m along the plank. Calculate the work done on the wheelbarrow by the worker. work done = Suggest one reason why the answer to is not equal to the answer to . The worker finds that walking up the plank pushing the wheelbarrow is even more inefficient than the answers in suggest. State what is meant by efficiency. Suggest one reason why this method of lifting the load onto the platform is so inefficient.
1. Motion, forces and energy  →  1.7.2. Work
1. Motion, forces and energy  →  1.7.1. Energy
1. Motion, forces and energy  →  1.7.5. Power
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3
shows a hot water tank that contains two electric heaters X and Y. X Y hot water out cold water in insulation Heater X is used during the daytime but heater Y is only used at night when electricity is cheaper. The tank is full of cold water and X is switched on. The temperature of all the water above X increases very quickly but the temperature of the water below X increases much more slowly. Explain the process that causes the water above X to increase in temperature. Heater Y remains switched off. Explain why the temperature of the water below heater X increases much more slowly than the temperature of the water above heater X. The hot water tank is covered in a thick layer of insulating material. The material is a plastic that contains a large number of small pockets of trapped air. Explain why this material is a good insulator.
2. Thermal physics  →  2.2.3. Melting, boiling and evaporation
2. Thermal physics  →  2.3.4. Consequences of thermal energy transfer
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4
Describe, in terms of molecules, the structure of a solid. shows a metal-worker heating a horseshoe to a high temperature before shaping it. horseshoe metal-worker The metal-worker then cools the horseshoe by dropping it into 8.0 kg of water at 18 °C. The final temperature of the water is 43 °C. The specific heat capacity of water is 4200 J / (kg °C). Calculate the thermal energy transferred to the water as the horseshoe cools. energy = The heat capacity of the horseshoe is 850 J / °C. Calculate the temperature of the horseshoe immediately before it is dropped into the water. temperature =
2. Thermal physics  →  2.2.2. Specific heat capacity
2. Thermal physics  →  2.2.3. Melting, boiling and evaporation
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5
The cable of a washing machine contains three separate wires. There is a fuse in one of the wires. Explain how the earth wire and the fuse work together to make the washing machine safer. State the name of the wire in which the fuse is connected. Explain why the fuse is connected into this wire. The cable of a hair-dryer contains only two wires. State the name of each of these wires. 1. 2. Suggest why the hair-dryer does not need an earth wire.
4. Electricity and magnetism  →  4.4.2. Electrical safety
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6
Phosphorus-32 (32 15 P) is an isotope of phosphorus that undergoes radioactive decay. The most common isotope of phosphorus is phosphorus-31. Describe the structure and composition of a neutral atom of phosphorus-31. State how an atom of phosphorus-32 differs from an atom of phosphorus-31. Phosphorus-32 decays by beta-particle emission to a stable isotope of sulfur. The half-life for this decay is 2.0 weeks. State how a nucleus of this isotope of sulfur is different to a nucleus of phosphorus-32. At time t = 0, a radioactive sample contains 3.2 × 1011 atoms of phosphorus-32. At the same moment, the sample contains no atoms of sulfur. This is shown by the cross on . On , plot a graph to show how the total number of sulfur atoms in the sample changes with t and draw a suitable curve. 1.0 × 1011 2.0 × 1011 3.0 × 1011 number of sulfur atoms 4.0 × 1011 2.0 4.0 t / weeks 6.0 8.0 State two precautions taken when storing or moving radioactive materials. 1. 2.
5. Nuclear physics  →  5.2.3. Radioactive decay
5. Nuclear physics  →  5.2.5. Half-life
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7
A bus leaves a bus-stop at time t = 0 and travels along a horizontal road until it reaches a second bus-stop. is the distance-time graph for the bus between t = 0 and t = 60 s. distance / m time / s The road on which the bus is travelling is straight except for a short, curved section. The bus travels around this circular curve between t = 21 s and t = 24 s. Describe how the motion of the bus between t = 0 and t = 10 s differs from its motion between t = 35 s and t = 40 s. Determine: the maximum speed of the bus during these 60 s maximum speed = the average speed of the bus between leaving the first bus-stop and arriving at the second bus-stop. average speed = State how velocity differs from speed. There are three periods during the 60 s when there is a non-zero resultant force acting on the bus. Complete the statements to indicate these three time periods and state the direction of the resultant force in that period. 1. Between t = and t = the direction of the resultant force is 2. Between t = and t = the direction of the resultant force is 3. Between t = and t = the direction of the resultant force is During the journey, the air resistance acting on the bus varies. State why the air resistance changes during the journey. On , mark and label with an M a time when the air resistance is a maximum value.
1. Motion, forces and energy  →  1.2. Motion
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8
A thin converging lens is made of a transparent material of refractive index 1.4. A ray of light travelling in air strikes the surface of the lens at an angle of incidence of 55°. Calculate the angle of refraction. angle of refraction = Place a tick (3) in one of the boxes in the third column of Table 8.1 to indicate how the light ray deviates and what happens to the speed of the light in the ray as it enters the lens. Table 8.1 direction of deviation speed of light away from the normal decreases away from the normal does not change away from the normal increases towards the normal decreases towards the normal does not change towards the normal increases State what happens to the frequency of the light in the ray as it enters the glass. The focal length of the lens is 2.5 cm. State what is meant by focal length. is a full-scale diagram that shows an object O of height 3.0 cm and the lens. O 1.0 cm 1.0 cm principal axis lens (full scale) By drawing on , locate and mark the image I of O. Determine the distance of I from the lens and calculate the magnification of O produced by the lens. distance = magnification = Describe how a converging lens is used in a camera.
3. Waves  →  3.2.3. Thin lenses
3. Waves  →  3.2.2. Refraction of light
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9
shows a permanent magnet lying on a piece of paper. paper magnet Underline the material in the list from which it is possible to make a strong, permanent magnet. aluminium copper glass iron mercury plastic steel Describe an experiment to plot the pattern and the direction of the magnetic field surrounding the magnet. You may draw on , if you wish. shows the N-pole of a magnet placed in front of the S-pole of a second magnet. J K – + N-pole S-pole A section of a horizontal, metal wire JK lies in the magnetic field between the two magnetic poles. End K of the metal wire is connected to the positive terminal of a battery and end J is connected to the negative terminal. Explain in terms of electrons, why there is a current in the wire and state the direction of the conventional current. The part of JK that is in the magnetic field experiences a force F. State the direction of F and describe how this direction is deduced. The equipment in is used in a similar experiment. The part of JK that lies between the poles of the magnets, now passes through a long iron tube that is fixed in position. The tube is shown in . J K – + iron tube JK is connected to the battery in the same way as before. State what happens to force F on the wire. Explain your answer. The iron tube and the wire JK are removed. A square, vertical coil is placed between the poles so that the plane of the coil lies in the magnetic field as shown in . N-pole S-pole square coil Explain why the coil tries to rotate when there is a current in the coil.
4. Electricity and magnetism  →  4.1. Simple magnetism and magnetic fields
4. Electricity and magnetism  →  4.5.3. Magnetic effect of a current
4. Electricity and magnetism  →  4.5.4. Forces on a current-carrying conductor
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