Question

Trajectories of two projectiles are shown in figure. Let $T_1$ and $T_2$ be the time periods and $u_1$ and $u_2$ their speeds of projection. Then
(1) $T_2>T_1$ (2) $T_1=T_2$ (3) $u_1>u_2$ (4) $u_1<u_2$

• A. 1, 2 and 3 are correct.
• B. 1 and 2 are correct.
• C. 2 and 4 are correct.
• D. 1 and 3 are correct.

Answer 1

Answer: (C)

Maximum height and time of flight depend on the vertical component of initial velocity
$H_1=H_2$
$\Rightarrow$ $u_{y_1}=u_{y_2}$
Here, $R=\frac{u^2\sin 2\theta }{g}=\frac{2(u\sin \theta )(u\cos \theta )}{g}$
$=\frac{2u_x{u}_y}{g}$
$R_2>R_1$
$\therefore$ $u_{x_2}>u_{x_1}$ or $u_2>u_1$