### SECTION A (25 Marks)

1.

The density of sulphuric acid is 0.9g/cm3. Calculate the volume of 1.8kg of the acid. ....................................................................................................................................

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3 marks

2.

Draw a micrometer screw gauge showing a reading of 5.85mm if the pitch of the screw gauge is 0.5mm.

1 marks

3.

The figure 1 (a) below shows a soap bubble blown towards the wide end of a funnel. The narrow end is then closed.

i) On the figure 1 (b) indicate, the position of the bubble after the narrow end is opened.

ii) Explain this observation.

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1 marks

4.

The figure 2 below shows air trapped in a J- shaped tube. What is the pressure exerted on the trapped air?( density of mercury 1600kg/m3 atmospheric pressure=1x105pa) (2 marks)

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2 marks

5.

A mass, m is suspended from a tight copper wire as shown in the figure below. The wire is then heated.

State and explain what was observed on the position of M as the wire was heated for sometime.

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2 marks

6.

Fig. 4 shows two possible arrangements of fins in a heat sink, a device that reduces accumulation of heat in electrical devices.

State with a reason which arrangement of fins makes the heat sink work better.

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2 marks

7.

Figure 5 shows a wheel spanner used to loosen a tight nut. The mechanic found it very difficult to use.

State with a reason the adjustment which he would make for the same force F to be sufficient to loosen the nut.

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2 marks

8.

Distinguish between stable and unstable equilibrium.

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1 marks

9.

The Figure 6(a) below shows a tennis ball hanging close to a water tap. When the tap is opened so that water flows, the ball is attracted to the stream as in figure (b)

Explain this observation

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2 marks

10.

Figure 7 shows a velocity-time graph for a moving object.

On the axes provided, sketch the displacement-time graph for the same motion.

1 marks

11.

Figure 8 shows a stack of coins. The one at the base is hit hard and ejected out of the stack. The remaining stack continues to slant in the same position,

Explain this observation

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1 marks

12.

Name the property of a spring that enables it to regain its original length when the load is removed.

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1 marks

13.

A column of air 24cm long is trapped by a column of mercury 10cm long in a horizontal tube with uniform cross-sectional area. If the atmospheric pressure is 76cm, determine the new height of air trapped in the tube when the tube is placed vertically.

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3 marks

14.

The figure 9 below shows an inverted test-tube which floats in water enclosed in a plastic bottle that is well corked.

When the sides of the plastic bottle are squeezed, the test-tube sinks. Explain this observation.

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1 marks

### SECTION B (55 Marks)

15.

The figure 10 shows microscope M focused on smoke particles inside a smoke cell P.

i) What causes the Brownian motion observed?

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ii) Identify the lenses marked A and B.

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iii) What should be incorporated in the set up to make the observation clearer?

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iv) Explain what would be observed if the particle of the air have the same size with smoke particles.

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b) The figure 11 below shows an oil patch made by a drop of oil placed on a dusty surface of water. 100 similar drops have a volume of 2mm3.
Calculate the approximate diameter of one molecule of oil (the diagram is drawn to scale).
D is the diameter of the oil film.

9 marks

16.

a) The figure 12 shows a graph obtained when 0.5kg hot liquid Naphthalene in an Aluminium can of mass 0.4kg was allowed to cool to room temperature.

i) State and explain the shape of the graph and the happenings in the Aluminium can at each stage of the cooling process.

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b) State three factors that affect the rate at which Naphthalene cools.

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c) Using kinetic theory of gases, explain how the rise in temperature of a gas causes a rise in itâ€™s the pressure when the volume is kept constant.
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12 marks

17.

The diagram in the figure 13 below shows a hydraulic jack system.

a) Name the parts labelled W and X

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b) Explain briefly how the device is used to raise the load at the position shown.

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c) Part W is left open to the atmosphere as indicated. Explain

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d) State two ways by which the mechanical advantage of the jack may be increased.

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e) One such hydraulic jack was used to lift air of mass 1200kg The cross section area of Q was 500cm2 and that of P was 5cm2. Determine the force exerted on the pump piston.

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12 marks

18.

i) On the figure, indicate all the forces acting on the sphere

ii) Find the tension in the cable.

b) A piece of metal weighing 3N in air,2N when totally immersed in water and 1.5N when totally immersed in liquid Q.

Calculate

i) the up thrust in water

ii) the upthrust in liquid Q.

iii) the relative density of the metal.

iv) the relative density of liquid Q

12 marks

19.

a) Define the term angular displacement.

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b) Figure 15 shows a device that may be used to control the speed of a vehicle.

Explain how the device may be used to control the speed.

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Determine

i) The maximum angular velocity.

ii) Angular acceleration during the last 1.5 minutes.

iii) How many revolutions the car made.

10 marks

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