Question

1. use the formula $i = mr^2$. show your work

a 40 kg child sits 0.5 m from the center of a seesaw.
b. the same child moves to 1.0 m from the center.

Explanation:

Step1: Calculate for part A

Substitute $m=40\ \text{kg}$, $r=0.5\ \text{m}$ into $I=mr^2$.
$I = 40\times(0.5)^2 = 40\times0.25 = 10\ \text{kg·m}^2$

Step2: Calculate for part B

Substitute $m=40\ \text{kg}$, $r=1.0\ \text{m}$ into $I=mr^2$.
$I = 40\times(1.0)^2 = 40\times1 = 40\ \text{kg·m}^2$

Answer:

A. $10\ \text{kg·m}^2$
B. $40\ \text{kg·m}^2$