Page 141 - Science Coursebook

9 End of unit questions

a Calculate the area of the brick in contact with the floor. Give your answer
2
in cm . [1]
b Calculate the pressure of the brick on the floor. [2]
c The diagram shows the molecules of a gas which is enclosed in a cylinder.
The piston is pushed inwards.

What has happened to the volume of the gas? [1]
d Explain why the pressure of the gas increases when the piston is pushed inwards. [1]

9.4 The diagram shows a force being used to make a spanner undo a nut.

60 N

0.2 m

a Calculate the moment of the force about the pivot. [2]
b Does the moment of the force act clockwise or anticlockwise? [1]
c The diagram shows a beam with two forces acting on it. The beam is balanced.

1.2 m 0.5 m 0.7 m

20 N F

Calculate the value of the force F. [3]

9 Forces in action 139