Question

A bullet fired from a gun has a mass $100g$ and velocity $1000km/hr$. What is its kinetic energy?

Choose the nearset value.

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

Answer 1

The correct option is A

3864 J

The mass of the bullet is $100g$ and the velocity of the bullet is $1000km/hr$

$K.E.=\frac{1}{2}m{v}^2$, where m is the mass of the bullet and v is the velocity of the bullet.

Mass $m=100g=0.1kg$

velocity $v=1000\frac{km}{hr}=1000\times \frac{1000}{3600}\frac{m}{s}$
$⟹v=277.7\frac{m}{s}$

Substituting the values of mass and velocity in the equation we get:

$K.E.=\frac{1}{2}\times 0.1\times {277.7}^2=3855.8J$