Question #5304e

2 Answers
Jan 25, 2018

3.57 meters

Explanation:

E_P=mgh

Where E_P is the potential energy
m is mass in kilograms
g is the acceleration of gravity on Earth
h is the height above ground (reference point)

Using the units given, you can identify that you have the mass and potential energy, and need height. Plug these numbers into the formula.

70J=2kg*9.8m/s^2*h

Simplifying the right-hand side gives 70J=19.6(kg*m)/s^2*h

Divide both sides by 19.6 kilograms meters per second squared on both sides of the equation to get the height.

3.57m=h

Jan 25, 2018

3.57m (or 3.5m)

Explanation:

GPE = mgh

where m is mass, in kg
g is gravitational field strength, in N//kg
h is height, in m.

h = (GPE)/(mg)

m = 2kg
g ~~ 9.81 (assuming that the question is set on Earth)
GPE = 70J

(GPE)/(mg) = 70/(2*9.81)

=70/19.62

h = 70/19.62

= 3.57m (3s.f.)

note: if you want to use 10N//kg for the value of g, the method is the same. the answer obtained is 7/2, which is 3.5m.