Physics - Roller Coasters and Relativity

Cells, batteries, generators all transfer energy to components in the circuit. 

1) When an electrical charge goes through a change in voltage, energy is transferred. 

2) Energy is given to the charge at the power source to raise it through a voltage.

3) The charge is given up when it passes through components in the circuit.

Electrical Energy = Voltage x Current x Time

Energy transfer is rarely 100% efficiant, there will almost always be wasted heat, noise energy etc.

Potential Energy = mass x g x height

'g' represents the 'acceleration of free fall', which on Earth, is always 10m/s² 

The proper name for potential energy is gravitational potential energy.

Sometimes, the equation will be written as:

Change in potential energy = mass x g x change in height.

When something is raised from ground level, it has potential energy as it has potential to give off energy of some sort. Eg. a kettle on a table has the potential to give off heat and noise energy.

E.g, A sheep of mass 47kg is slowly raised through 6.3m. Find the gain in potential energy.

Answer: It's even easier than before, you just plug the numbers into the formula. 

P.E = mgh  = 47 x 10 x 6.3  = 2961J