5054_w15_qp_22
A paper of Physics, 5054
Questions:
11
Year:
2015
Paper:
2
Variant:
2

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Aeroplanes fly at high altitudes where the temperature is well below 0 °C. Ice that forms on an aeroplane can fall to earth and strike the ground. shows a block of ice falling from an aeroplane as it approaches an airport. block of ice (not to scale) The mass of the falling block of ice is 1.2 kg and the gravitational field strength g is 10 N / kg. Calculate the weight of the block of ice. weight = is the speed-time graph for the block of ice as it falls to the ground. speed m / s 2.0 4.0 6.0 8.0 time / s 10.0 12.0 At first, the acceleration of the block of ice is equal to the acceleration of free-fall. The acceleration of the block then decreases to zero as the block reaches terminal velocity. As the block of ice falls, the force F of air resistance acting on the block changes. 1. State the value of F at time = 0. F = 2. State the value of F at time = 10.0 s. F = 3. Explain why F changes. State the energy change that takes place when the block is falling at terminal velocity. Using information from , determine the maximum kinetic energy of the block when it is falling to the ground with terminal velocity. maximum kinetic energy = The block strikes the ground and it stops moving. This impact causes some of the ice to melt. The specific latent heat of fusion of ice is 330 J / g. Calculate the maximum possible mass of ice that melts as a result of the impact. mass = In practice, the mass of ice that melts on impact is less than the value calculated in . Suggest two reasons for this. 1. 2. As the solid ice melts, it changes into liquid water. Describe, in terms of molecules, how ice differs from liquid water.
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Thin wire, covered in plastic insulation, is used to make a solenoid (long coil). The solenoid is connected to a sensitive ammeter. shows the N-pole of a steel magnet placed next to the solenoid. A solenoid steel magnet X Y N Point X and point Y are on the axis of the solenoid. Explain why plastic is an electrical insulator. Explain why the magnet is not made from 1. aluminium, 2. iron. In one experiment, the magnet in is moved to the left and passes into the solenoid. The N-pole of the magnet travels from Y to X at a constant speed. As it moves, the ammeter shows a small current. Explain why there is a current in the solenoid when the magnet is moving. The N-pole travels from Y to X in 0.14 s. As it moves, the current shown on the ammeter is 0.045 mA. The resistance of the solenoid is 1.2 Ω. Calculate 1. the potential difference (p.d.) across the solenoid, potential difference = 2. the charge that passes through the solenoid as the N-pole moves from Y to X. charge = In a second experiment, the speed of the N-pole is greater than its speed in the first experiment. It now takes only 0.070 s to travel from Y to X. A current in the same direction is shown on the ammeter. State and explain how the size of this current compares with the size of the current in the first experiment. The same quantity of charge passes through the coil in both the first and second experiments. Explain why this is the case. State two ways in which the equipment shown in can be used to produce a current in the solenoid that is in the opposite direction. 1. 2.
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The proton number (atomic number) of the element lead is 82. The isotope lead-209 (209 82Pb) is radioactive and decays by the emission of beta-particles. Describe the composition and structure of a neutral atom of lead-209. A nucleus of lead-209 emits a beta-particle. State how the composition of the nucleus produced differs from the original nucleus. Complete the table in to show the relative ionising effects of the three types of ionising radiation produced by radioactive decay. least strongly ionising most strongly ionising A sample containing lead-209 nuclei is used to produce a beam of beta-particles. The beta-particles enter a magnetic field. The magnetic field is perpendicular to the direction of travel of the beta-particles. The beta-particles travel from left to right. shows that the direction of the magnetic field is out of the page. magnetic field out of the page beam of beta-particles On , sketch the path of the beta-particles in the magnetic field. An industrial technician uses a detector to measure the background count rate in a laboratory. State what is meant by background radiation. Suggest two major sources of background radiation. 1. 2. The average reading for the background count measured by the technician is 16 counts / minute. He then brings a sample that contains a radioactive isotope of lead close to the detector and he finds that the new count rate is 92 counts / minute. The half-life of this isotope is 3.3 hours. Determine the count rate measured using the detector after 6.6 hours. count rate =