Key stage 3 Science Exercise
1. A layer of oil helps to reduce __________ on the surface.
2. There are _________ types of frictions.
3. Different types of surfaces create _______ amount of friction.
4. There are four types of friction; static, fluid, sliding and ________ .
5. Waves transfer energy from __________ to another.
6. These are two types of waves; transverse and _________ waves.
7. When two waves meet, their displacement combine _____. This is called _______ .
8. Both light waves and water waves are ________ waves.
9. ________ reflection is when light hits an object and reflects in lots of different directions.
10. When the surface is smooth, the light will reflects on the same angel as it hits the surface. This is called ________.
11. A light wave is also called _______.
12. When light wave passes from a fast medium to slow medium, it bends. This is called _______ .
13. The cornea and __________ lens help us to focus on an object.
14. The coloured part of the eye is called _________ .
15. The images are captured on the _______.
16. We can see things because reflected __________ enters into our eyes.
17. Smooth shiny surface such as mirror _________ light well.
18. Dull and rough surface do not _____ light well.
19. Light travels in a __________ lines from a light source to our eyes.
20. Our eyes can detect _________ because of the light.
Answer1. friction 2. 4 3. different 4. rolling 5. one point 6. longitudinal 7.shortly, superposition 8. transverse 9. diffuse 10. specular reflection 11. light ray 12.refraction 13. convex 14. iris 15. retina 16. light 17. reflects 18. reflect 19. straight 20. images