Question

A ball of mass $100\text{g}$ is projected with a velocity of $50\text{m/s}$ at ${37}^{\circ }$ from horizontal. Using the concept of impulse, find the magnitude of change in velocity of ball in $2\text{s}$ (Take g = 10 m/s${}^2$)

• A. $70\text{m/s}$
• B. $20\text{m/s}$
• C. $30\text{m/s}$
• D. $10\text{m/s}$

Answer 1

The correct option is B $20\text{m/s}$

Using, $|J|=|F|\times t=|\Delta p|=m|\Delta V|$
$\Rightarrow |\Delta V|=\left(\frac{t}{m}\right)|F|$
Only force acting on the ball is $mg$
$\therefore |\Delta V|=\frac{t}{m}\times mg=gt$
$=10\times 2$
$=20$ m/s