Physics 0625/51 May/June 2019: question paper and mark scheme

Question

In this experiment, you will determine the weight of a metre rule using a balancing method. Carry out the following instructions, referring to Fig. 1.1. 50.0 cm mark P metre rule a b bench 100 0 90.0 cm mark pivot Fig. 1.1 (a) Place the metre rule on the pivot. Place the load P with its centre on the metre rule at the 90.0 cm mark. Keeping the load P at the 90.0 cm mark, adjust the position of the metre rule on the pivot so that the metre rule is as near as possible to being balanced. Measure, and record in the first row of Table 1.1, the distance a from the 90.0 cm mark to the pivot. Measure, and record in the first row of Table 1.1, the distance b from the pivot to the 50.0 cm mark. Repeat the steps above, placing the centre of the load P at the 85.0 cm, 80.0 cm, 75.0 cm and 70.0 cm marks. Record all values of a and b in Table 1.1. Table 1.1 a / cm b / cm [3] (b) Plot a graph of a / cm (y-axis) against b / cm (x-axis). You do not need to begin your axes at the origin (0, 0). [4] (c) Determine the gradient G of the graph. Show clearly on the graph how you obtained the necessary information. G = …… [1] (d) Calculate the weight W of the metre rule using the equation W = G × P, where P = 1.0 N. W = …… [1] (e) Suggest one practical reason why it is difficult to obtain accurate readings for a and b in this type of experiment. …… [1] (f) Use the balance provided to measure the mass of the metre rule. mass = …… [1] [Total: 11]

Question

In this experiment, you will determine the resistance of a resistance wire. Carry out the following instructions, referring to Fig. 2.1. power supply A l metre rule B 100 sliding resistance contact C wire V Fig. 2.1 (a) (i) Switch on. Measure the current I in the circuit. I = …… [1] (ii) Place the sliding contact C at a distance l = 20.0 cm from B. Measure, and record in Table 2.1, the potential difference V across the length l of the resistance wire. V Calculate, and record in Table 2.1, . l Repeat the procedure using l values of 40.0 cm, 60.0 cm, 80.0 cm and 100.0 cm. Switch off. Table 2.1 l / cm V/V V V l cm 20.0 40.0 60.0 80.0 100.0 [4] V (b) Look carefully at the values of in Table 2.1. l (i) Tick the box to show your conclusion from the results. V is approximately constant. l V is decreasing as V increases. l V is increasing as V increases. l V There is no simple pattern for in the results. l [1] (ii) Justify your conclusion by reference to your results. …… [1] V (c) Calculate the resistance of 100 cm of the resistance wire using the equation R = , where V I is the potential difference across 100 cm of the resistance wire. Use the value of current I from part (a)(i). Give your answer to a suitable number of significant figures for this experiment and include the unit. R = …… [3] (d) In this type of experiment, it is sensible to keep the temperature of the resistance wire as close to room temperature as possible. Suggest one way to minimise the rise in temperature of the resistance wire. …… [1] [Total: 11]

Question

In this experiment, you will investigate the rate of cooling of water under different conditions. A greater rate of cooling occurs if there is a greater change in the temperature during the same period of time. Carry out the following instructions referring to Fig. 3.1. You are provided with a beaker labelled A and a can labelled B. thermometer lid clamp stand hot water beaker A bench Fig. 3.1 (a) Use the thermometer to measure room temperature θR. θR = …… [1] (b) Pour 200 cm3 of hot water into beaker A. Place the lid on the beaker and place the thermometer in the beaker, as shown in Fig. 3.1. Record in Table 3.1 the temperature θ of the hot water at time t = 0. Immediately start the stopclock. After 30 s, measure the temperature θ shown on the thermometer. Record the time t = 30 s and the temperature reading in Table 3.1. Continue recording the time and the temperature readings every 30 s until you have six sets of readings. [3] Table 3.1 Table 3.2 beaker A can B t/s θ / ºC t/s θ / ºC (c) Pour 200 cm3 of hot water into can B. Place the lid on the can and place the thermometer in the can. Record in Table 3.2 the temperature θ of the hot water at time t = 0. Immediately start the stopclock. After 30 s, measure the temperature θ shown on the thermometer. Record the time t = 30 s and the temperature reading in Table 3.2. Continue recording the time and temperature readings every 30 s until you have six sets of readings. [2] (d) Look carefully at the readings in Table 3.1 and in Table 3.2. (i) Tick the box to show your conclusion from the readings. The water in the beaker has a greater rate of cooling than the water in the can. The water in the beaker has a smaller rate of cooling than the water in the can. There is no significant difference between the rates of cooling of the water in the beaker and the can. [1] (ii) Justify your conclusion by reference to your readings. …… [2] (e) A student in another school carries out the experiment and reports that the rate of cooling of the water in the can is different from the rate of cooling of the water in the beaker. He plans a change to the experiment to find out whether this difference in the rates of cooling is caused by • the matt black surface of the can being a better radiator of thermal energy than the shiny surface of the beaker • the metal of the can being a better conductor of thermal energy than the material of the beaker. Suggest two suitable changes to the apparatus that the student could make. 1. …… 2. …… [2] [Total: 11]

Question

A student is investigating the work required to pull a box containing some masses up a sloping wooden board. Fig. 4.1 shows the board and the box. Plan an experiment to investigate how the work required to pull the box up the slope depends on the mass of the box and its contents. Work done is calculated using the equation: work done = force × distance moved in the direction of the force. You are not required to carry out this experiment. The following apparatus is available to the students: a wooden board a box with a length of string attached a selection of masses that fit in the box a metre rule an electronic balance. In your plan, you should: • list any other apparatus that you would use • explain briefly how you would carry out the investigation, including the measurements you would take • state the key variables that you would control • draw a suitable table, with column headings, to show how you would display your readings (you are not required to enter any readings in the table) • explain how you would use the results to reach a conclusion. You may add to the diagram if it helps your explanation. box string wooden board masses Fig. 4.1 …… [7] [Total: 7]