Question

The variation of horizontal displacement (x) of a projectile with time (t) is as shown in the figure. If the angle of the projection is ${60}^o$, find the velocity of projection is ____ ${ms}^{-1}$

• A. $35$
• B. $65$
• C. $30$
• D. $50$

Answer 1

The correct option is A $35$

Let horizontal velocity $v_x$ and velocity of projection $v$.

From the Displacement-Time graph, Velocity= Slope of the graph. $\Rightarrow v_x=\frac{70}{4}=\frac{35}{2}$,

Angle of projection is ${60}^o$. $\Rightarrow v_x=vcos\left({60}^o\right)$ $\Rightarrow v=35m{s}^{-1}$