Question

A vertical pole of $5.6m$ height casts a shadow $3.2m$ long. At the same time find the height of a pole which casts a shadow $5m$ long.

• A. $8.75m$
• B. $6.75m$
• C. $7.75m$
• D. None of these

Answer 1

The correct option is A $8.75m$

At, same time angle made by tip of pole and height of shadow is same, for every pole because sun rays follow straight path.

So, tangent of angle which is ratio of height of pole and length of shadow will also be same as angle is same.

it is given that vertical pole of $5.6m$ height casts a shadow $3.2m$ long.

So, $\text{ratio}=\frac{\text{Height of pole}}{\text{length of shadow}}=\frac{5.6}{3.2}=\frac{7}{4}$

Now, we have to find a pole whose shadow is $5m$ long

So, $\text{length of pole = ratio x length of shadow}$

$=\frac{7}{4}\times 5=8.75m$

Hence, option $A$ is correct.