Question

1. a 0.5 kg apple falls from a tree branch 8 meters high. what is its potential energy before it falls?

78.4 j
9.8 j
19.6 j
39.2 j

Explanation:

Step1: <Formula for potential energy>

The formula for potential energy is \( PE = mgh \), where \( m \) is the mass, \( g \) is the acceleration due to gravity (\( g = 9.8\ m/s^{2} \)), and \( h \) is the height.

Step2: <Substitute values into formula>

Given \( m = 0.5\ kg \), \( h = 8\ m \), and \( g = 9.8\ m/s^{2} \), substitute into \( PE=mgh \). So \( PE=(0.5)(9.8)(8) \).

Step3: <Calculate the result>

First, \( 0.5\times9.8 = 4.9 \), then \( 4.9\times8=39.2\ J \).

Answer:

39.2 J