### SECTION A (25 Marks)

Answer all the questions in the section in the spaces provided
1.

Figure below shows a vernier calipers being used to measure the internal diameter of a test tube

Record the correct reading of the diameter if the instrument has a zero error of -0.02cm. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................

2 marks

2.

A uniform wooden bar of length 1M and mass 800g is pivoted at 40cm as shown in figure 2 below.

Calculate the above value of force A if the system is in equilibrium. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................

3 marks

3.

In figure 3 below, air is blown into the tube. Indicate the level of water in the beaker X and Y.

3 marks

4.

In the set up shown in the figure 4 below, water near the top of the boiling tube boils while at the bottom it remained cold

Explain the observation

................................................................................................................................................... ...................................................................................................................................................

1 marks

5.

A bottle of soda always has space between the cap and the top of the liquid. Explain ................................................................................................................................................... ...................................................................................................................................................

1 marks

6.

The figure 5 below shows a U- tube containing two liquids L1 and L2 of densities 0.5g/cm3 and 0.8g/cm3 respectively floating on a water surface.

If the system is in equilibrium, determine the ratio h1 : h2 (3mks) ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................

3 marks

7.

A body weighing 100N in air is found to weigh 80N when fully immersed in a certain fluid. Account for the difference in the two weighs. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................

1 marks

8.

Sketch a density â€“ temperature graph for water being heated from 00C to 100C on the axes provided

8 marks

9.

Two identical helical springs are connected in series. When a 50g mass is hang at the end of the springs, it produces an extension of 2.5cm. Determine the extension produced by the same mass when the springs are connected in parallel

................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................

3 marks

10.

A gas is heated from 200C to 600C at constant pressure. Determine the ratio of its volumes at the two temperatures. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................

2 marks

11.

. In a vacuum flask how is heat loss by radiation minimized. ...................................................................................................................................................

1 marks

12.

. A ball of mass 100g is kicked horizontally from the top of a cliff. If the ball takes 4 seconds to hit the ground, determine the height of the cliff ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................

2 marks

13.

. In terms of kinetic theory of matter, explain why evaporation causes cooling. ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................

2 marks

14.

. An electric heater rated1KW 240V is used to raise the temperature of a 5kg copper block from 150C to 330C. If the specific heat capacity of copper is 400JKg-1K-1 and assuming no heat is lost to the surrounding. Calculate the time taken

3 marks

### SECTION B (55 Marks)

15.

a) Explain why a body moving in a circular path with constant speed is said to be accelerating. (1mk) ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................

b) A wooden block of mass 200g is placed at various distances from the center of a turntable, which is rotating at constant angular velocity. It is found that at a distance of 8.0cm from the center, the block just starts to slide off the table. If the force of friction between the block and the table is 0.4N, Calculate: i) The angular velocity of the turntable (3mks)

................................................................................................................................................. ................................................................................................................................................. .................................................................................................................................................
................................................................................................................................................. .................................................................................................................................................

ii) The force required to hold the block at a distance of 12cm from the center of the turntable (3mks) ................................................................................................................................................. ................................................................................................................................................. ................................................................................................................................................. .................................................................................................................................................
c) A block of mass 400g is now placed at a distance of 8.0cm from the centre of the turntable
in (b) above and the turntable rotated at the same angular velocity. State with a reason whether or not the ball slide off (2mks)
................................................................................................................................................. ................................................................................................................................................. .................................................................................................................................................

9 marks

16.

. a) Define the term work (1mk)

................................................................................................................................................. ................................................................................................................................................. .................................................................................................................................................

b) The graph below shows extension of a material when a force is applied:-

i) Does the material obey Hookeâ€™s law (2mks) ...................................................................................................................................... .....................................................................................................................................

ii) State the elastic limit (1mk) ......................................................................................................................................

iii) Determine the material constant. Give your answer in SI units. (3mks) ...................................................................................................................................... ...................................................................................................................................... ......................................................................................................................................

iv) Determine the work done in stretching the material by 2.5cm, using the graph.(3mks) ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ......................................................................................................................................

c) State two factors that affect the strength of a spring. (2mks) ...................................................................................................................................... ......................................................................................................................................

12 marks

17.

. a) Differentiate between heat capacity and specific heat capacity of a substance (1mk) ...................................................................................................................................... ......................................................................................................................................

b) An immersion heater rated 1000W is used to heat a block of ice of mass 500g initially at -100C until the all water evaporates at 950C. Assuming that all the heat supplied is used to heat the ice, calculate the time in minutes for the whole process to take place. (Take specific heat capacity of water as 4200J/KgK, specific heat capacity of ice=2100J/KgK , specific latent heat of fusion =3.35x105J/Kg and specific latent heat of vaporization 2.26 x105J/Kg) (6mks) .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..........................................................................................................................................................

c) State two differences between Boiling and Evaporation. (2mks) .......................................................................................................................................................... ..........................................................................................................................................................

d) The set â€“ up below was used to investigate the effect of pressure on melting point of ice.

i) It was observed that the wire gradually cuts through the ice block, but leaves it as one piece. Explain this? (3mks) ................................................................................................................................................. ................................................................................................................................................. ................................................................................................................................................. .................................................................................................................................................
ii) State the effect of using a cotton thread of a wire. (1mk) ................................................................................................................................................. .................................................................................................................................................

13 marks

18.

. a) State the pressure law (1mk)

................................................................................................................................................. .................................................................................................................................................

b) The diagram below shows a set-up that a student used to investigate the pressure law.

i) State the measurements that should be taken in this experiment (2mks) ................................................................................................................................................. ................................................................................................................................................. ................................................................................................................................................. .................................................................................................................................................

ii) Explain how the measurement in (i) above may be used to verify Pressure law (4mks) ................................................................................................................................................. ................................................................................................................................................. ................................................................................................................................................. ................................................................................................................................................. ................................................................................................................................................. .................................................................................................................................................

iii) Name one limitation of the gas laws. (1mk) ................................................................................................................................................. .................................................................................................................................................
iv) Hydrogen gas of volume 2400cm3 at 540C and pressure of 2.4N/m2 is compressed until its volume is 300cm3 at a pressure of 6N/m2. Determine the temperature of the gas after this compression. (3mks) ................................................................................................................................................. ................................................................................................................................................. ................................................................................................................................................. .................................................................................................................................................

11 marks

20.

. a) State Archimedes Principle (1mk)

................................................................................................................................................. ................................................................................................................................................

. b) The figure below shows a block of mass 50g and density 2000kg/m3 submerged in a certain liquid and suspended from uniform beam by means of a string. A mass of 40g suspended from the other end of the beam puts the system in equilibrium.

i) Determine the upth

10 marks

Back Top