word problem

Question

you did 150 joules of work lifting a 12 kg backpack. how high did you lift the  backpack.

Answer 1

The concept here is energy and elevation is being considered.  Knowing this, we must use the formula for potential energy:

 

PE = mgh

 

where:

PE = potential energy = 150 joules = 150 kg m²/s²

m = mass = 12 kg

g = acceleration due to gravity = 9.81 m/s²

h = elevation

 

Manipulation the formula, we obtain

 

h = PE / mg

h = (150 kg m²/s²) / [(12 kg)(9.81 m/s²)]

h = (150 kg m²/s²) / (117.72 kg m/s²)

h = 1.27 m