2. Energy is the ability to do work or cause change.
The unit for measuring energy is the Joule (J).

3. Energy

6. Types of Potential Energy
Chemical potential energy
The nutrients in the banana are
chemicals which are stored
in the food.
Gravitational potential energy
The skydiver has potential
energy due to his height above the ground

7. Types of Potential Energy
Elastic potential energy
The arrow has potential energy
due to the elastic nature of the bow
Energy is stored in the nucleus of an atom.
Nuclear potential energy

10. On Earth the acceleration of gravity is 9.8 m/s2, and has the symbol g.

11. A roller coaster car of mass 465 kg rolls up a hill with a vertical height of 75 m from the ground. What is the potential energy relative to the ground? GPE = mass x acceleration of gravity x height

12. A bar weighing 550 g is raised 3. 0 m off the ground
A bar weighing 550 g is raised 3.0 m off the ground. What is its potential energy? GPE = mass x acceleration of gravity x height

13. What is the mass of a girl if she was raised 2
What is the mass of a girl if she was raised 2.00 m off the ground and has a potential energy of 555 J? GPE = mass x acceleration of gravity x height

20. Practice: KE = ½ mv2
A .10-Kilogram bird is flying at a constant speed of 8.0 m/s. What is the birds KE?
A 70.0 Kg man is walking at a speed of 2.0 m/s. What is the KE?

21. Practice: KE = ½ mv2
A 1400 Kg car is moving at a speed of 25 m/s. How much KE does the car have?
*A 50.0 Kg Cheetah has a KE of 18,000 J. How fast is the cheetah running?

23. KE = ½ mv2 PE = mgh ME = KE + PE
A car weighing 5,500 kg, travels at a speed of 55 km/h up a 15 m hill. What is its mechanical energy?
KE = ½ mv2 PE = mgh ME = KE + PE