Question

A body falling for 2 sec. covers a distant equal to that covered in next second taking g value as $10m/s^2$. Then s equals

• A. 30 m
• B. 10 m
• C. 60 m
• D. 20 m

Answer 1

The correct option is A 30 m

Given that,

A body falling for $2sec$.

$g=10m/s^2$

Using equation of motion

Distance travelled by the body in 2 sec is

$s=ut+\frac{1}{2}g{t}^2$

$s=u\times 2+\frac{1}{2}g\times 2\times 2$

$s=2u+2g$..... (I)

Distance travelled by the body in next second is

$s=u+\frac{g}{2}(2n-1)$

$su+\frac{g}{2}(2\times 3-1)$

$s=u+\frac{5g}{2}$.....(II)

From equation (I) and (II)

$2u+2g=u+\frac{5g}{2}$

$4u+4g=2u+5g$

$u=\frac{10}{2}$

$u=5m/s$

Now, put the value of u in equation (I)

$s=2\times 5+2\times 10$

$s=30m$

The distance s is equal to the $30m$.

Hence, Option A is correct.