**Paper 2 H - SAMPLE SET 1 Q9 ****Answers**

**Questions**

(9)

**Figure 24**shows a submarine underwater.The motor in the submarine turns the gear wheels shown in

**Figure 25**.(a) Gear wheel A rotates clockwise through one complete turn.

Which of these is correct for gear wheel B? (1)

Which of these is correct for gear wheel B? (1)

(b) A bubble of gas escapes from the submarine.

The volume of the bubble is 23.0cm

The pressure of the gas inside the bubble is 297kPa.

The bubble rises to the surface without changing temperature.

Calculate the volume of the bubble when it reaches the surface.

Atmospheric pressure = 101kPa

Use an equation from the formula sheet. (3)

The volume of the bubble is 23.0cm

^{3}.The pressure of the gas inside the bubble is 297kPa.

The bubble rises to the surface without changing temperature.

Calculate the volume of the bubble when it reaches the surface.

Atmospheric pressure = 101kPa

Use an equation from the formula sheet. (3)

volume = ............................................... cm^{3}

(c) A student is interested in the way that submarines are controlled.

She has several regular wooden blocks, a set of weights and a tank of water. Wood floats in water.

The student plans to immerse the wooden blocks fully in the water and investigate the relationship between the upthrust and the weight of water displaced.

Describe how she should determine **one** of the variables in this investigation.
(2)

*(d) **Figure 26** shows the submarine stationary and submerged at a depth of 10m.

Explain how pumping water into and out of the buoyancy tank affects the depth
of the submarine below the surface.
(6)

**(Total for Question 9 = 12 marks)**