Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Motion in a straight Line

Question:

If a ball is thrown vertically upwards with speed u, the distance covered during the last t seconds of its ascent is

Options:

$\frac{1}{2}gt^2$

$ut-\frac{1}{2}gt^2$

$(u-gt)t$

$ut$

Correct Answer:

$\frac{1}{2}gt^2$

Explanation:

The correct answer is Option (1) → $\frac{1}{2}gt^2$

The time taken by the ball to reach the highest point

$=u –gn ⇒n=\frac{u}{g}$

$S_n=un-\frac{1}{2}gn^2$

and $S_{n-t}=u(n-t)-\frac{1}{2}g(n-t)^2$

$∴ s =S_n-S_{n-t}=\frac{1}{2}gt^2$