1.1. A cube made from aluminium is placed on a horizontal surface, as shown in Fig. 1.1.

The following measurements were made on the cube:

mass = 0.59 ± 0.01 kg

length of one side = 6.0 ± 0.1 cm

Calculate the pressure produced by the cube on the surface.                                                                               

1.2. (i) Calculate the percentage uncertainty in the pressure.

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(ii) State the pressure, with its actual uncertainty.

pressure = .................... ± .................... Pa  [2]

1.3. Calculate the density of aluminium with its uncertainty. 

Express your answer to an appropriate number of significant figures.

density .................. ± .................. g cm⁻³  

1.4. The student uses vernier callipers to measure the length of the side of the cube. After completing the experiment, he realises that when the callipers are fully closed, the reading is not zero. 

(i) State and explain whether this introduces a random error or a systematic error in the readings of the length.

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(ii) Explain why the readings are precise but not accurate.

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