Question

A projectile is thrown from the ground with an initial velocity of $(4\hat{i}+3\hat{j})$$m/s$. It reaches its greatest height above the ground after (Take $g=10m/s^2$)

• A. $0.20s$
• B. $0.30s$
• C. $0.45s$
• D. $4.5s$

Answer 1

The correct option is B $0.30s$


Let $u$ be the initial velocity of the projectile
According to question,
And as shown in the figure,
$u\sin \theta =3\text{m/s}$ and
$u\cos \theta =4\text{m/s}$
Time taken to reach maximum height is gven by
$T_{max}=\frac{u\sin \theta }{g}=\frac{3}{10}=0.3s$