Grade 9 Science 4th Quarter Mechanical Energy.pptx

Physics

1. Mechanical Energy Energy of either an object in motion or the energy that is stored in objects by their position. ME= PE + KE

2. Potential Energy Energy is stored or held in readiness. (Energy at rest) E P = mgh Kg.m^2/s^2

3. A box has a mass of 5.8 kg. The box is lifted from the garage floor and placed on a shelf. If the box gains 145 J of potential energy, how high is the shelf?

4. A man climbs onto a wall that is 3.6 m high and gains 2268 J of potential energy. What is the mass of the man?

5. An 800g ball is pulled up a slope as shown in the diagram. Calculate the potential energy it gains. 20 cm 50 cm

6. Kinetic Energy The moving energy. (Energy in motion) E K = ½ mv^ 2

7. What is the kinetic energy of a 150 kg object that is moving with a speed of 15 m/s?

8. An object has a kinetic energy of 25 J and a mass of 34 kg, how fast is the object moving?

9. An object moving with a speed of 35 m/s and has a kinetic energy of 1500 J, what is the mass of the object?

10. An 800g ball is rolling down a slope as shown in the diagram. Calculate the total mechanical energy it gains. 25 cm 0.01 m/s