1. Mechanics Physics12 Energy transformations Mechanics Physics12 Energy transformations

2. Mechanics Physics12 Energy transformations Mechanics Physics12 Energy transformations

3. Mechanics Physics12 Energy transformations Energy change... ‘transforms’ ‘transfers’ or It is better to say that energy has been transferred between two objects than to say that energy has been transformed. “chemical potential energy has been transformed into gravitational potential energy”

4. Mechanics Physics12 Energy transformations Energy transferred by... HEAT(ing) WORK(ing) or T gradient displaced force

5. Mechanics Physics12 Energy transformations Work done & the Joule work done = force x distance moved (in the direction of the force) The Joule is defined as the energy transferred when a force of 1 N is displaced a distance of 1 m. W = FΔs

6. Mechanics Physics12 Energy transformations Mechanics Physics12 Energy transformations Resolving vectors in work calculations...  F Fsin  Fcos  work done = force x distance moved (in the direction of the force)

7. Mechanics Physics12 Energy transformations Potential energy ΔE grav = m g Δh Strictly, this is change in potential energy. This potential energy is released by an object doing work on another object, or itself. Q1 & 2, p41

8. Mechanics Physics12 Energy transformations Efficiency Q1-5, p48-49 efficiency = useful energy out total work done or energy in

9. Mechanics Physics12 Energy transformations Transformation Transfer Work Watts Key words you should now recognise... Kinetic energy Potential efficiency