Page 127 - Physics Coursebook 2015 (A level)

Chapter 7: Matter and materials
14 a
Describe why the pressure of the atmosphere is less at the top of a mountain than at the bottom. [1]
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b
Figure 7.24 For End-of-chapter Question 14.
Figure 7.24 shows a U-tube, open at both ends, which contains two different liquids, X and Y, that do
not mix. The numbers on the metre rule are distances in centimetres. The density of liquid Y is 800 kg m−3.
i Explain how Figure 7.24 shows that liquid Y has a greater density than liquid X. [2]
ii Calculate the density of liquid X. [3]
iii ExplainwhythepressureintheU-tubeisthesameonbothsidesofthemanometeratlevelL. [1] iv CalculatethepressurecausedbyliquidintheU-tubeatlevelL. [2]
liquid Y
L
liquid X
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