## QUESTIONS

1. State three topics you studied in primary Science which is related to Physics. (3mks)
2. State two four career opportunities which require you to study physics. (4mks)
3. Give reasons of studying physics in School. (3mks)
4. Give three problems which can be associated with use of knowledge gained in physics. (3mks)
5. State how physics is applied in (2mks)
1. Geography
2. Home science
6. State the three basic quantities (3mks)
7. Express the following into cm2. (2mks)
1. 8.5m2
2. 0.0008cm2
8. The mass of 20cm3 of wood was found to be 0.04kg. calculate the density of wood.
1. In kg/m3 (2mks)
2. Ing/cm3 (2mks)
9. How would you find the area of irregularly snapped surface (2mks)
10. Name five laboratory apparatus that can be used to measure the volume of a liquid. (5mks)
11.
1. Define time and state its SI units. (2mks)
2. Calculate the number of seconds in a day. (2mks)
12. Define force and give its SI units (2mks)
13. State three types of forces. (3mks)
14. Explain why water wets a paper but mercury does not. (2mks)
15. State two factors which affects surface tension of a liquid. (2mks)
16. State the difference between mass and weight (4mks)
17. Define scalar and vector quantities and give example of each. (4mks)
18. Define the term pressure and give its SI unit. (2mks)
19. Explain how drinking straw works. (4mks)
20. State two applications at the principle of transmission of pressure. (2mks)
21. A density of a liquid is 1.5gcm3. Calculate the volume of 4kg of the liquid in cm3. (3mks)
22. A mixture consists of 40cm3 of water and 60cm3 of liquid X. If the densities of water and liquid x are 1.0g/cm3 and 0.8g/cm3 respectively, calculate the density of mixture. (3mks)
23.
1. What is friction force? (1mk)
2. Give two advantages of frictional force. (2mks)
24. Calculate the pressure due to water experienced by a fish 20m below the surface of the sea (Density of sea water. 1030kg/m3) (3mks)
25. The force of gravity on the moon is one sixth of that on the earth. Determine the weight of a 12kg mass on the moon. (2mks)
26. A box of mass 5kg has dimensionâs 10mx5mx3m. determine the maximum pressure exerted by the box on a flat surface. (3mks)

## MARKING SCHEME

1. State three topics you studied in primary science which are related to Physics. (3mks)
• Properties of matter, pressure, floating and sinking states of matter magnetic and non-magnetic materials.
• Energy, heat, sound light electricity
• Making work easier, see-saw, beam balance friction
2. State two four career opportunities which require you to study physics. (4mks)
• Computer science
• Mechanical engineering
• Civil engineering
• Agricultural engineering
• Architecture
• Astronomy
3. Give reasons of studying physics in School. (3mks)
• To understand the working of various instruments used in everyday life
• Explain natural phenomena e.g rainbow
• To prepare for career related to physics
4. Give three problems which can be associated with use of knowledge gained in physics. (3mks)
• Atomic bomb can be very dangerous to life. It can be harmful to human and cause death.
• Cyber-crimes, committed through internet
• Accidents in nuclear reactors are fatal.
5. State how physics is applied in (2mks)
1. Geography
• Instruments used in geography have products of physics
• Formation of sea and land breeze is explained in physics
2. Home science
• Physics knowledge is used to make kitchen equipment.
6. State the three basic quantities (3mks)
• Length
• Mass
• Time
• Temperature
• Thermo dynamies
• Amount of substance
7. Express the following into cm2. (2mks)
1. 8.5m2
• 85000cm2
2. 0.0008cm2
• 0.0008cm2
8. The mass of 20cm3 of wood was found to be 0.04kg. calculate the density of wood.
1. In kg/m3 (2mks)
• 2000kg/m3
2. In g/cm3 (2mks)
• 2g/cm3
9. How would you find the area of irregularly snapped surface (2mks)
• Divide the surface into squares of known areas cm2 and then count the number of squares.
• Area=number of complete squares + number of 1 couple squares/2
10. Name five laboratory apparatus that can be used to measure the volume of a liquid. (5mks)
• Measuring cylinder
• Pipette
• Burette
11.
1. Define time and state its SI units. (2mks)
• Time is a measure of duration of an event SI units is second(s)
2. Calculate the number of seconds in a day. (2mks)
• 60x60x24=86400 seconds
12. Define force and give its SI units (2mks)
• Force is a push or a pull. Its SI unit is Newton (N)
13. State three types of forces. (3mks)
• up thrust - electric
• Frictional - cohesive
• Centripetal - tension
• Nuclear -surface tension
14. Explain why water wets a paper but mercury does not. (2mks)
• Because the adhesive force between the water molecules and the paper molecules is greater than the cohesive force between water molecules.
15. State two factors which affects surface tension of a liquid. (2mks)
• Impurities
• temperature
16. State the difference between mass and weight (4mks)
• Weight is a measure of the pull of gravity on the object
• Mass is the quantity of matter present in an object
17. Define scalar and vector quantities and give example of each. (4mks)
• Scalar is a quantity which bas magnitude oly e.g mass area, density and volume.
• vector, is a quantity with both magnitude and direction e.g force, velocity
18. Define the term pressure and give its SI unit. (2mks)
• Pressure is the force acting normally per unit area. SI unit N/M2 or NM-2
19. Explain how drinking straw works. (4mks)
• When using straw a person sucks air out fit reducing the pressure in it. The atmospheric pressure acting on the surface of the liquid being greater than pressure inside, the straw pushes the liquid up the straw.
20. State two applications at the principle of transmission of pressure. (2mks)
• Hydraulic lift
• Hydraulic brake
• Hydraulic press
21. A density of a liquid is 1.5gcm3. Calculate the volume of 4kg of the liquid in cm3. (3mks)
• Density=1.5gcm-3
Mass= 4kg= 4000g
Volume= mass
Density
4000 = 2666.67cm3
1.5
22. A mixture consists of 40cm3 of water and 60cm3 of liquid X. If the densities of water and liquid x are 1.0g/cm3 and 0.8g/cm3 respectively, calculate the density of mixture. (3mks)
• Density= mass of liquid x + mass of water
Volume of liquid x + volume of water
= (0.8 x 60) + (1.0x40)
40 + 60
48+40 =0.88g/cm3
100
23.
1. What is friction force? (1mk)
• Force that opposes relative motion between two surfaces in contact
2. Give two advantages of frictional force. (2mks)
• Enable us to walk
• Braking of cars
• Lighting match stick
24. Calculate the pressure due to water experienced by a fish 20m below the surface of the sea (Density of sea water. 1030kg/m3) (3mks)
• P=hpg
=20x1030x10
=206000n/m2
25. The force of gravity on the moon is one sixth of that on the earth. Determine the weight of a 12kg mass on the moon. (2mks)
• W=mg
=12x1/6x10
=20N
26. A box of mass 5kg has dimensionâs 10mx5mx3m. Determine the maximum pressure exerted by the box on a flat surface. (3mks)
• Pressure is greatest when area is smallest
• Smallest area=5x3=15m2
• Force exerted by the box=weight of the box        5x10
=50N
P=f/a
=50/15=3.33n/m2