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Unit summary

Check your knowledge and understanding

1. Which is easier to beat into the ground: a metal 4. In J.K. Rowling’s book, Harry Potter and the Prisoner
rod or a pipe of the same diameter? Explain your of Azkaban, there is a scene in which Harry inflates
answer using key words from this unit. his aunt using magic, causing her to float up to
textbooks nis edu kz
the living room ceiling. Estimate the volume of
2. Imagine you blow up balloons for a party. All of
them are round, except one, which is elongated. the aunt floating in the air. With which object’s
Explain why this elongated balloon does NOT volume can you compare that of the aunt?
contradict Pascal’s Law.

3. Diving is a popular sport throughout the world.
Experienced divers use different methods to
stay under the water as long as possible. They
hold their breath and breathe under water
using special apparatus – aqualungs or scuba
equipment. Explain whether diving is possible
using a simple rubber pipe to breathe through
(one end in the diver’s mouth and the other end
sticking out of the surface of the water). Suggest
a simple device for breathing under water.

Assess your learning

Reflect on how well you met the learning objectives of this unit. Use the worksheet provided by
your teachers to develop your own targets.

How confident am I?

I can …
explain what pressure is, using key words from this unit

calculate the pressure of a solid on a support, using an equation
explain how pressure occurs in gas and why liquid exerts pressure, using knowledge about the structure
of matter
explain how solids, liquids and gases exert external pressure

derive an equation to calculate the pressure of a liquid on the bottom of a container
explain what upthrust force is and discuss the reasons for its occurrence, using key words

apply Archimedes’ Principle and the equation for calculating the upthrust force
explain the conditions necessary for buoyancy

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