Question

a 40 kg runner is running at a speed of 3 m/s. how much kinetic energy does the runner have? remember : $e_k = \frac{1}{2}mv^2$ $e_k = ?$ j

Explanation:

Step1: Identify given values

Mass \( m = 40 \, \text{kg} \), speed \( v = 3 \, \text{m/s} \), and the formula for kinetic energy \( E_K=\frac{1}{2}mv^2 \).

Step2: Substitute values into formula

Substitute \( m = 40 \) and \( v = 3 \) into \( E_K=\frac{1}{2}mv^2 \):
\( E_K=\frac{1}{2}\times40\times(3)^2 \)

Step3: Calculate step by step

First, calculate \( (3)^2 = 9 \). Then, \( \frac{1}{2}\times40 = 20 \). Finally, \( 20\times9 = 180 \).

Answer:

180