Question

With what speed should a body be thrown upwards so that the distance traversed in $5^{th}$ second and $6^{th}$ second are equal? (Take $g=9.8m/s^2$)

• A. $5.84\text{m/s}$
• B. $49\text{m/s}$
• C. $\sqrt{98}\text{m/s}$
• D. $98\text{m/s}$

Answer 1

The correct option is B $49\text{m/s}$

This could only be possible when the total time taken in upward journey will be $5\text{s}$

Using first equation of motion for the upward motion in the $5^{th}$ second, we get

$v=u+at$
$\Rightarrow 0=u-g\left(5\right)$
$\therefore u=gt=9.8\times 5=49\text{m/s}$