Physics- Wor. Energy and Power/ Unit 7

What is meant by the term energy???

Energy is the ability to do work.

Give 7 forms of energies.

Heat energy, sound energy, electrical energy, kinetic energy, gravitational potential energy, light energy and chemical energy.

What is meant by the term ‘workdone’ ???

Work is done when a body moves in the direction of the force applied.

Is there motion when there is no work???

NO.

What is the formulae for ‘workdone’???

Workdone=Force x Distance

What is the formulae for ‘force’???

Force=work * distance

What is the formulae for ‘distance’???

Distance= work * force

What is the unit for force???

Newton. N

What materials is used to meaure newton???

Spring Balance and Newton Meter.

What is the unit of workdone???

Joule, J

What is the unit for distance???

Metre, m

HOw to calculate ‘weight’???

Mass X Gravity

How much is gravity on Earth???

10m/s²

What is the formulae for Kinetic Energy???

½ × mass × v²

What does the V i n the kinetic energy's formulae mean???

Speed.

What is teh unit of speed???

m/s

What is the unit of mass???

KIlogram, kg.

What is meant by the term kinetic energy???

KInetic energy is the energy possessed by an object due to its motion.

What are the two things that kinetic energy depends on???

• The mass of the object.

• THe speed of the object.

What is meant by the term gravitational potential energy???

Gravitational Potential Energy is the energy possessed by a body due to its position above ground level.

What is the formulae for ‘Gravitational Potential Energy’???

GPE = mgh

Gravitational Potential Energy = Mass x Gravity x Height.

What is the unit for ‘Height’???

Metre, m

Where an object falls down at its maximum height, is there more kinetic energy or pgravitational potential energy???

Yes!

When the object is falling down but in the midway, is there more kinetic energy or more gravitational potential energy???

NO. They are equal as it's falling midway.

When the object is done falling from its height, is theer more kinetic energy or more gravitationl potential energy???

There will be no kinetic energy as the object stopped moving, so there is more gravitational potential energy on the object as gravity is acting.

What is meant by the term power???

Power is the rate at which work is done.

What is the unit of power???

Watt, W.

What is the 2 formulaes for power???

• Power = workdone÷timetaken

• Power = Energy÷time

Power depends on what???

• Depends on work done,

• Depends on time taken.