How many joules of potential energy does a 1.2-kg book gain when it is elevated 4.0 ?
Express your answer to two significant figures and include the appropriate units.
PE = F*h = mg*h = 1.2*9.8 * 4 = 47.04 J.
To calculate the potential energy gained by the book, we need to use the formula:
Potential energy = mass * acceleration due to gravity * height
Given:
Mass (m) = 1.2 kg
Height (h) = 4.0 m
Acceleration due to gravity (g) = 9.8 m/s^2
Let's substitute the values into the formula:
Potential energy = 1.2 kg * 9.8 m/s^2 * 4.0 m
Simplifying the equation:
Potential energy = 47.04 kg·m²/s²
Since the joule (J) is the unit for energy in the International System of Units (SI), we can convert the answer to joules by recognizing that 1 joule is equal to 1 kg·m²/s². Therefore:
Potential energy = 47.04 J
Rounding to two significant figures and including the appropriate units:
The book gains 47 J of potential energy when elevated 4.0 m.