
Tim E. answered 10/22/15
Tutor
5.0
(43)
Comm. College & High School Math, Physics - retired Aerospace Engr
potential gravitational energy (PE) is simply :
PE = m*g*h where g = 9.81 m/s2 (earth's gravity at the earth surface)
(note: PE is always referenced from an arbitrary height)
so, PE = mgh = 7*9.81*1.5 = 103.005 (kg*m2/s2) or Joules
(note: units multiplied are: kg*(meters/s2)*meters, which also = 1 Joule)