Energy Stores and Transfers (Slides)

@@**Define Energy.**@@

Energy is the ability to do work

%%What is the unit of energy?%%

Joule

==What is the Energy flow diagram for a rocket?==

Chemical energy→Kinetic energy+ gravitational potential energy+ thermal energy+ light energy + sound energy

^^What is the Principle of Conservation of energy?^^

Energy cannot be created or destroyed It can only be transferred from one form to another

@@Answer the question.@@

1\.0 x 105J

### ^^Define efficiency.^^

Efficiency is the percentage of energy supplied that is usefully transferred

### ==What is the equation for efficiency?==

Efficiency = useful energy output / total energy input x 100%

### %%When a filament lamp is supplied with 100J of energy, it produced 15J of useful light. Find its efficiency.%%

15%

### ==A tidal-power station is expected to produce 32TJ of energy (1TJ=1012J ) when the tides provide it with energy 100TJ of gravitational potential energy. What is the efficiency of the power station?.==

32%

### ^^A tungsten-filament lamp is 4% efficient. How much electrical energy must be supplied to the lamp each second when it produce 6J of light per second?^^

150J

### %%What is the Equation of Gravitational Potential Energy?%%

g.p.e = mg x h

> ### ^^Answer the following question.^^

400KJ

### ==It is claimed that superman can jump 200metres vertically upwards. If he has a mass of 100kg,by how much does his g.p.e increase?==

200KJ

### %%**What is the equation for Kinetic energy?**%%

K.e = 1/2 x mv^2

### Answer the following question.

300KJ

### @@How much kinetic energy is stored by a bullet with a mass of 10.5g travelling at 553m/s?@@

1605KJ

### Usain Bolt has a mass of 86kg.When he runs at 12m/s ,what is his kinetic energy?

6192KJ