Question

A body is thrown upwards with velocity $100m/s$ and it travels $5m$ in the last second of its upward journey. If the same body is thrown upward with velocity $200m/s$, what distance will it travel in the last second of upward journey? (Given $g=10m/s^2)$.

• A. $5m$
• B. $10m$
• C. $20m$
• D. $25m$

Answer 1

The correct option is A $5m$

we know the relation

$S=u+\frac{a}{2}(2n-1)$

for $case=1u=\mathrm{100}m{s}^{-1},a=-10m{s}^{-2},s=5m$

$5=100+\left(\frac{-10}{2}\right)(2n-1)$

we get $n=10seconds$

for case $u=200{ms}^{-1},a=-10m{s}^{-1},V=0{ms}^{-1}$

$\text{time}=\frac{v-u}{a}\Rightarrow \frac{0-200}{-10}\text{time}=20\text{seconds}$

here $n=20seconds$

$S=u+\frac{a}{L}(2n-1)$

$S=20\dot{0}-5\left(39\right)$

$S=5m$

so the answer is (A) $5m$