Changes in energy stores List the different types

Changes in energy stores - List the different types of energy stores and how they are transferred - Describe the change in energy stores for a torch and a toy car Conservation and dissipation of energy - What is the law of the conservation of energy? - What does energy dissipation mean? - Describe useful and wasted enegy Electrical power - - -- Give the definition of power - -How is power calculated using energy/work done and time? - Give an example of power using motors - t is power? Energy and efficiency How is energy efficiency calculated? What is the calculation for power efficiency? What does efficiency mean? Conservation and dissipation of energy H Energy and work - What is work done? - Write an equation triangle with units including work done, force and distance Gravitational potential energy Stores - Give a definition of GPE - Write an equation triangle including GPE, height, mass and gravitational field strength Kinetic energy - Give a definition of kinetic energy - Write an equation triangle including kinetic energy, mass and velocity - Write an equation to calculate elastic potential energy (not required to learn).

Changes in energy stores 1. Describe the changes in energy stores when you fire a bow and arrow 2. Give 3 examples of a system changing energy stores Conservation and dissipation of energy 1. When a washing machine transfers electrical energy where does the electrical energy get transferred to? 2. What does conservation of energy tell you? Electrical power 1. What is the power if a radio transfers 20 J of energy every 4 s 2. What is the power of a TV if it transfers 6000 J of energy in 5 minutes Energy and efficiency 1. What is the efficiency of a washing machine that transfers 1500 J energy usefully and wastes 500 J every second 2. How efficient is a 20 W energy efficient light bulb if 12 W are transferred as light every second Conservation and dissipation of energy H Energy and work 1. Calculate the work done by a machine using a force of 25 N to move a box up by 2. 5 m 2. If the work done to move a ball 3 m is 65 J what force was used? Gravitational potential energy Stores 1. What is the increase in GPE if a box of 60 kg is lifted 2. 5 m off the ground (g = 9. 8 N/kg) 2. What would happen to GPE if you were on the moon? Kinetic energy 1. What is the kinetic energy of a parachutist of 75 kg travelling at 50 m/s? 2. What is the max speed of a road sweeper (mass 50 kg) if 2500 J of kinetic energy is transferred