Question

A bullet of mass $100g$ has shot a speed of $108km/hr$ towards the target. What would be its kinetic energy?

• A. 3864 J
• B. 4240 J
• C. 2586 J
• D. 6580 J

Answer 1

The correct option is

A

45 J

The mass of the bullet is $100g$ and the speed of the bullet is $108km/hr$
$K.E.=\frac{1}{2}m{v}^2$, where m is the mass of the bullet and v is the speed of the bullet.
Given, $\text{m =100 g = 0.1 kg}$

$v=108km/hr=108\times \frac{5}{18}=30m/s$
$K.E.=\frac{1}{2}m{v}^2=\frac{1}{2}\times 0.1\times {30}^2=45J$