On Your Answer Sheet, Write in the Correct Letter for Each Question

9L Quick Quiz

On your answer sheet, write in the correct letter for each question.

9La 9Lb

1 How can you increase the pressure beneath a nail? 1 The pressure in liquids and gases is caused by: A Use less force to hit it. A the particles pressing down. B File the point down so its area is bigger. B the particles pushing up. C Make the point sharper so its area is bigger. C the particles moving sideways. D Make the point sharper so its area is D the particles moving in all directions and smaller. colliding with things. 2 Which of these statements is not true? 2 When a gas is compressed: A Skis stop you sinking in snow because they A the particles bump into the walls of the reduce the pressure. container less often. B Sharp knives work best because they B the pressure drops. reduce the pressure. C the particles become more spread out. C Bulldozers use caterpillar tracks to reduce the D the pressure increases. pressure beneath them. 3 Why does a dam at the end of a lake need to be D Drawing pins have a sharp point to wider at the bottom? increase the pressure. A Water pressure is greater near the surface of the 3 Which is not a unit for pressure? water. A pascals B There is more water pressure at the bottom of the B newtons per square metre lake. C kilograms C To use up more concrete. D newtons per square centimetre D Water pressure decreases with depth. 4 A basketball player weighs 500 N. The area of 4 Which graph shows how air pressure changes with one of his trainers is 250 cm2. When he puts all height? his weight on one foot, how much pressure does he put on the ground? A 0.5 N/cm2 B 2 N/cm2 C 250 N/cm2

D 125 000 N/cm2

of 2 Exploring Science edition 316 © Pearson Education Limited 2009

9L Quick Quiz (continued)

9Lc 9Ld 1 A hydraulic system: A uses air to smooth out bumps. 1 The moment of a force is: B uses air to send a force from one place to A how far it moves. another. B how long it takes to work. C uses a liquid to send a force from one place to C its turning effect. another. D the distance of a force from a pivot. D uses a solid to send a force from one place to 2 You are opening a can of paint with a screwdriver. another. You apply a force of 10 N, 20 cm from the pivot. 2 Liquids are used in hydraulic systems because: What is the moment of the force? A the particles are close together A 2 N m (a liquid can be compressed). B 20 N m L B the particles are close together C 200 N m (a liquid cannot be compressed). D 2000 N m C the particles have gaps between them 3 What is a seesaw that is ‘in equilibrium’? (a liquid can be compressed). A a balanced seesaw D the particles have gaps between them B a seesaw with the same weight on each side (a liquid cannot be compressed). C a seesaw with both people the same 3 Which statement does not explain why distance from the middle hydraulics are used for car brakes? D a wooden seesaw A Compressed air in the system is cheap. 4 What is the distance from the pivot of the boy B The pipes can follow the shape of the car floor. on the seesaw? C The force from the driver’s foot can be boy: 300 N × ? m girl: 450 N × 2 m increased. D The system can send a force from the brake pedal to the brakes. 4 The diagram shows a hydraulic system. What force is produced by piston Y?

A 1 m B 2 m C 3 m A 18 N D 4 m B 20 N C 180 N D 540 N