Question

1. a cannonball with a mass of 9kg is moving at 39 m/s. how many joules of kinetic energy does it have? $ke = \frac{1}{2} mv^2$

175.5 j
180.89 j
6,844.5 j
8,908.8 j
clear all

Explanation:

Step1: Identify given values

Mass \( m = 9 \, \text{kg} \), velocity \( v = 39 \, \text{m/s} \), formula \( KE=\frac{1}{2}mv^{2} \).

Step2: Substitute into formula

First, calculate \( v^{2} = 39^{2}=1521 \). Then, \( \frac{1}{2} \times 9 \times 1521 \).

Step3: Perform multiplication

\( \frac{1}{2} \times 9 = 4.5 \), then \( 4.5 \times 1521 = 6844.5 \).

Answer:

6,844.5 J (corresponding to the option with 6,844.5 J)