Question

A projectile is thrown at $40\sqrt{2}\text{m/s}$ with an angle ${45}^{\circ }$ with horizontal. What will be the magnitude of velocity of the projectile after $1\text{sec}$ of its journey.

• A. $30\text{m/s}$
• B. $40\text{m/s}$
• C. $50\text{m/s}$
• D. $60\text{m/s}$

Answer 1

The correct option is C $50\text{m/s}$


$u_y=40\sqrt{2}\sin {45}^{\circ }=40\text{m/s}$
after $1\text{sec}$,
$v_y=40+(-10)\left(1\right)$
$=30\text{m/s}$
$u_x=40\sqrt{2}\cos {45}^{\circ }=40\text{m/s}$
after $1\text{sec}$,
$v_x=40+\left(0\right)\left(1\right)$
$=40\text{m/s}$
$v_{\text{net}}=\sqrt{{30}^2+{40}^2}=50\text{m/s}$