-
If the elevation of the Sun changes from 30° to 60°, then the difference between the lengths of shadows of a pole 15 metre high, is
-
- 7.5 metre
- 15 metre
- 10 √3 metre
- 5 √3 metre
Correct Option: C
AB = Height of pole = 15 metre
∠ACB = 60°; ∠ADB = 30°
In ∆ABC,
| tan 60° = | ⇒ √3 = | BC | BC |
| ⇒ BC = | = 5√3 metre | √3 |
In ∆ABD,
| tan 30° = | BD |
| ⇒ | = | √3 | BD |
⇒ BD = 15 √3 metre
∴ Required difference
= BD – BC = (15√3 - 5√3) metre
= 10 √3 metre
