An electric heater has two power settings. One setting is 0.5 kW and the other is 1.5kW. One kWh of electricity costs 11 pence. Calculate how much you would save if you used the heater 12 hours on the 0.5 kW setting instead of the 1.5 kW setting.

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final

20) what is a magnetic field? 21) in which direction do magnetic field lines always point? 22) sketch a diagram showing how a plotting compass points around a 23) name two magnetic poles that will: a) attract each other b) repel each other. 24) explain why you can use a compass to navigate. 25) what's an electromagnet? 26) list two ways to increase the strength of an electromagnet. 27) the wire in a simple motor feels a force when a current flows through it. why is this? i need answers to check mine

The momentum of a man riding his bicycle downhill can be calculated. the bicycle and the man have a combined mass of 40 kg. the velocity of the bicycle is 10 m/s. calculate the momentum.