Energy Stores and Transfers (Slides)

Define Energy.

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