Water flows along a horizontal pipe of cross sectional area 48cm² which has a constriction of cross-sectional area 12cm² at one place. If the speed of water at the constriction is 4m/s, calculate the speed in the wider section.           (3mks)

The figure below represents the arm of a lift pump with a force F being applied by the person drawing water. Determine the value of F the just pushes the arm downwards.        (3mks)

Kariuki identifies an abandoned circular water well of diameter 2.1m as a breeding zone for mosquitoes. He intends to use engine oil to control the breeding by pouring it in the surface of water. Given that the thickness of a molecule in the oil is  1.635 X 10^-9 m , determine the minimum volume of oil he requires.          (3mks)

Give a reason why alcohol in glass thermometer cannot be used when boiling water is used in an experiment.        (1mk)

Two similar razor blades are placed one on a wooden block and the other on a soft iron block as shown in the figure.

It was observed that the razor blade on the wooden block was attracted to the magnet while the one on the soft iron block was not. Explain the observation.           (2mks)

A car battery requires topping up with distilled water occasionally. Explain why this is necessary and why distilled water is used.         (2mks)

A soldier standing some distance from a wall blows a whistle and hears its echo 1.8 seconds later. How far is the wall from the soldier?    (speed of sound in air = 330m/s)            ( 3 marks)

The figure below shows two materials , one being a magnet and another a magnetic material.

1. 1. Which material is a magnet?                                                    (1mk)

1. 2. Label the poles of the magnet in (a)  above                              (2mks)

1. 3. Explain the difference in arrangement of the compass needles in materials P and Q    (2mks)

1. 4. Using domain theory of magnetism, explain why the strength of a magnet cannot be increased beyond a certain limit.       (2mks)

When washing clothes , it is easier to remove the dirt using soap in warm water than cold water. Explain                     (2mks)

The figure below shows a section of a micrometer screw gauge with a thimble scale of 50 divisions. When the spindle is in contact with the anvil , the device reads 0.25mm. if the screw gauge is used to measure the diameter of a spherical ball.

1. state the actual diameter of the ball          (2mks)

2. calculate the volume of the ball in SI units    (3mks)