FORTY points to whoever can help me with this! Thanks!

P. S. GUESS stands for Given Info, Understood (like what is it asking you), Equation (the formula), Substitute the variables, and Solve

A roller coaster is going down a hill. _ energy is changing into _ energy.
A roller coaster is going up a hill. _ energy is changing into _ energy.
A car engine burns gasoline in order to get moving. _ energy is changing into _ energy.

4. What is the mass of an object that is hanging 12.6m above the surface of the earth and has a potential energy of 2778.3J?
G U E S S

5. Calculate the kinetic energy of a truck that has a mass of 2900 kg and is moving at 55 m/s.
G U E S S

6. An object with a kinetic energy of 16,000J has a velocity of 8m/s. What is its mass?
G U E S S

And then there's three more in the pictures included. Thanks so much and remember to wash your hands!