Question

Can anyone help me with these few questions when even I try to the formula there always wrong :/

If a 6.0-kilogram box is moved from the floor to a storage compartment 2.0 meters above the floor, by how many joules does its gravitational potential energy change?

A 0.1-kilogram ball rolls across the floor at a speed of 2 meters per second. Another 0.1-kilogram ball rests ona shelf 1 meter above the floor. Which ball has more energy?

Find the mass of a ball on a roof 30 meters high, if the ball’s gravitational potential energy is 58.8 joules.

I dont want answers I just want some help

Answer 1

OK - you are dealing with 2 forms of energy

Potential energy (PE) - the energy a body has by virtue of its height (in a gravity field) above a datum.
The way to work out the PE is
PE = mgh wher m= mass, g = gravity acceleration of earth, and h = height above the datum (ground normally)

Kinetic energy (KE) ids the energy a body has by virtue of its speed.

The way to work out KE is
\[KE = \frac{ mv ^{2} }{ 2 }\]

Where m = mass of the moving body and v = velocity

In your questions you have all the information to work out the amount of these types of energy for each situation.

In each case if m is in kg, v is in m/s and g is m/s^2 then the Energy will be in Joule

Answer 2

wow thank you