Question

A body is thrown with a velocity of $[4\hat{i}+3\hat{j}]m/s$. The maximum height attained by the body is $(g=10m{s}^{-2})$

• A. $2.5m$
• B. $0.8m$
• C. $0.9m$
• D. $0.45m$

Answer 1

The correct option is D $0.45m$

$u_x=u\cos \theta =4$
$u_y=u\sin \theta =3$

$u=\sqrt{v_x^2+v_y^2}=\sqrt{4^2+3^2}=5$

$\Rightarrow \tan \theta =\frac{3}{4}\Rightarrow \sin \theta =\frac{3}{5},$

$\cos \theta =\frac{4}{5}$

$\Rightarrow h_{max}=\frac{u^{2}si{n}^2\theta }{2g}=\frac{5^2(3/5{)}^2}{2g}=0.45m$