Question

a 28 kg second grader is playing tag, he is running at a speed (velocity) of 1.0 meters per second. calculate his kinetic energy.

Explanation:

Step1: Recall kinetic energy formula

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

Step2: Identify values

Given $m = 28\space kg$ and $v = 1.0\space m/s$.

Step3: Substitute into formula

Substitute $m$ and $v$ into the formula: $KE=\frac{1}{2}\times28\times(1.0)^2$.

Step4: Calculate

First, $(1.0)^2 = 1$. Then, $\frac{1}{2}\times28\times1 = 14$.

Answer:

14 joules (or 14 J)