Shadows are formed when opaque objects block the passage of light. The length of a shadow is different at different times of the day. The size of shadow is dependent on many aspects including the size of sourcе of light, distance between the source of light and object, and distance between the screen and the object.

Jolly is 120 cm tall. She plotted a graph of the length of her shadows at different times of the day.

Observe the graph carefully. Now, answer the following questions.

(a) When is the length of Jolly's shadow the shortest? Why?

(b) When is the length of Jolly's shadow the longest? Why?

(c) What can you conclude from the graph?

(d) Will the shape of the graph differ from individual to individual?

(a) Jolly's shadow length is shortest at 12:00 PM (noon) because at noon the Sun is highest in the sky, so sunlight falls more vertically so that least sunlight is blocked and hence, shortest shadow is produced.

(b) Jolly's shadow length is longest at 8:00 AM (early morning) because in the morning the Sun is low on the horizon, so rays strike at a shallow angle so that maximum sunlight is blocked and thus long shadow is produced.

(c) From the graph we can conclude that shadow length of an object depends on the Sun’s position (time of day) such that shadow length decreases from morning to noon and increases from noon to evening.

(d) No, the shape of the graph will not differ from individual to individual because here the graph shows that the shadow length of any object is dependent on sun's position not on object's size.