Question

Calculate the kinetic energy of a 30 g bullet fired at 200 m/s.

Answer 1

Step 1: Identify the formula needed to solve this problem.

The formula for kinetic energy (KE) is:

KE = 1/2m~v^2

m = mass

v = velocity

Step 2: Make a list of the values given in the question.

mass (m) = 30 g

velocity (v) = 200 m/s

$\frac{1}{2} m {v}^{2} \\ \frac{1}{2} \times 30 \times {200}^{2} \\ 15 \times 40000 \\ = 600000$

Answer 2

Answer:

6 × 10⁵ J

Explanation:

Kinetic Energy of a moving mass is defined as, half of the product of it's mass and the square of it's velocity.

$\boxed{ \mathsf{K.E. = \frac{1}{2} m( {v})^{2} }}$

• Mass of the bullet (m) = 30 g
• velocity (v) = 200 m/ s

$\implies\mathsf{K.E. = \frac{1}{2} \times 30 \times ( {200})^{2} }$

$\implies\mathsf{K.E. = 15 \times 4 \times {10}^{4} }$

$\implies\mathsf{K.E. = 60 \times {10}^{4} }$

$\implies \underline{\mathsf{K.E. = 6 \times {10}^{5} J }}$