Question

what is the kinetic energy of a 145 kg football player moving at 0.42 m/s? 28.64 j 12.79 j 5.8 j 32.67 j clear all

Explanation:

Step1: Recall kinetic - energy formula

The formula for kinetic energy is $K = \frac{1}{2}mv^{2}$, where $m$ is the mass and $v$ is the velocity.

Step2: Substitute given values

Given $m = 145$ kg and $v=0.42$ m/s. Substitute into the formula: $K=\frac{1}{2}\times145\times(0.42)^{2}$.

Step3: Calculate the result

First, $(0.42)^{2}=0.1764$. Then, $\frac{1}{2}\times145\times0.1764 = 72.5\times0.1764 = 12.789\approx12.79$ J.

Answer:

12.79 J