Grade 9/ 1st term exam

Vernier calipers read to one tenth of a millimetre.

What reading shows this precision?

• 3.3 cm

• 3.31 cm

• 3.310 cm

• 3.312 cm

Which list contains only scalar quantities?

• Acceleration, displacement, mass

• Acceleration, distance, speed

• Displacement, mass, velocity

• Distance, mass, speed

A room measures 4.0m × 3.0m × 2.0m.

The density of the air in the room is 1.3kg/m³.

What is the mass of air in the room?

• 0.054 kg

• 18 kg

• 24 kg

• 31 kg

A man weighs 600N. He runs up a staircase of total height 4.0 m in 3.0 s.

How much useful power is needed to do this?

• 450 W

• 800 W

• 2400 W

• 7200 W

A block of metal has a mass of 2.0 kg. Its specific heat capacity is 800J/(kg⁰C).

The block is supplied with 2400 J of energy. What is the rise in temperature?

• 0.17 ⁰C

• 0.67 ⁰C

• 1.5 ⁰C

• 6.0 ⁰C

The efficiency of an electrical generator is 65%.

Which useful output can be expected if the energy input to the generator is 12 kJ?

• 4.2 kJ

• 7.8 kJ

• 19 kJ

• 780 kJ

A 2 kg mass is moving at constant speed. The kinetic energy of the mass is 400 J. What is the speed of the mass?

• 0.4 m/s

• 20 m/s

• 200 m/s

• 400 m/s

Power is measured in watts.

What is the correct symbol for millions of watts ?

• mw

• mW

• Mw

• MW

How does heat transfer through vacuum take place?

• By conduction, convection and radiation

• By conduction only

• By convection only

• By radiation only

To raise the temperature of a 2.0 kg block of metal by 20 ⁰C, energy of 5.2 kJ is needed.

What is the value of the specific heat capacity of the metal?

• 0.13 J /(kg⁰C)

• 52 J/(kg⁰C)

• 130 J /(kg⁰C)

• 52000 J/(kg⁰C)