Questions on Light
Q2. The diagram shows a lighthouse on a rock. It is night-time and there are boats at A, B, C, D and E moored in the water.
(a) On which boat, A, B, C, D or E, would the light from the lighthouse be brightest?
A
1 mark
(b) Each boat makes a shadow on the water.
(i) Draw a cross (X) on the diagram to show where the shadow of boat A will be.
The centre of a cross (X) drawn in the shaded area between boats A and B
Do not accept the centre of the cross below the water line or above the shaded area
1 mark
(ii) Explain why the shadow forms there.
any one from
light cannot go through the boat - the boat is opaque
llight travels in straight lines and cannot bend round the boat.
1 mark
(c) The weather changes and the fog horn on the lighthouse makes a loud sound. On which boat, A, B, C, D or E, would the sound of the fog horn be quietest?
E
1 mark
(d) Inside the lighthouse there is a powerful lamp and some mirrors. The diagram shows the lamp and a mirror. A ray of light from the lamp is shown. Carefully draw the ray which is reflected from the mirror. Use a ruler.
Normal to the mirror
Angles of incidence and reflection should be approximately equal, even if the reflected ray is not horizontal. If the reflected ray has been drawn without using a ruler, do not award this mark
2 marks
Maximum 6 marks