Question

a boy, 1.5 fall with speed, 3m/s along a straight path passing under a lamp hanging at height o of 3m then​

Answer 1

Correct Question:-

→ A 1.5m tall boy stands at a distance of 3m from a lamp post and casts a shadow of 4.5m on the ground find the height of lamp post by trignometric ratios.

Given:-

• Height if the boy = 1.5m

• Distance away from the Lamp = 3m.

• Height of Shadow casted = 4.5m

To Find :-

• The Height of the lamp by Trignometric Ratio.

Solution :-

We should find the height of the Lamp by using Trigonometric ratios.

• Let AB be boy = 1.5m

• CD Be the Lamp = x

• OB be the shadow casted by the boy = 4.5m

• BD be the distance between boy and the lamp.

So, In the figure,

In /\ AOB,

• => tanø = AB/OB

In /\ COD

• => tanø = CD/OD = CD/(OB+BD)

Therefore,

AB/OB = CD/(OB+BD)

=> 1.5+4.5 = CD/(4.5+3)

$\bold{ \red{★Hence \: CD = 2.5m}{} }{}$

___________________________________