- What is the difference between voltage and current?
- An electric whisk in a bakery has two motors, each with an average power of 1500W. The whisk is used for 4 hours each day, 7 days a week. Electricity costs 18p per kilowatt-hour. Calculate the cost of the electricity used by the whisk in one week.
- An electric Iron rated at 2600 W contains a steel plate, heated to a working temperature of 215°C. Room temp=18°C. Deduce whether the plate could reach its working temperature in less than 1 minute. Mass (steel plate)=890g & C (steel)=450J/kg/K
- Houses lose majority of their energy through the roof and windows. State the three methods of energy transfer. For the roof and windows respectively, describe one adaptation that could be made to improve their efficiency and explain their method.
- A footballer kicks a ball vertically upwards. Initially, the ball is stationary. His boot is in contact with the ball for 0.050s. The average resultant force on the ball during this time is 180N. The ball leaves his foot at 20m/s. Calculate the impulse