Physics P1 and P2 revision mat Flashcards
Write the formula for:
Work done
Work done = Force x distance
Write the formula for GPE Gravitational energy
GPE = Mass x gravitational field x height
Write the formula for Kinetic energy (KE)
1/2 x mass x velocity2
Write the formula for power
Power = energy/time
What are the units for power?
Watts
What are the units for
Word done
Joules
Name 3 thermal conductors
Copper
Aluminium
gold
(any metal)
Name 3 thermal insulators
Plastics
woods
glass
(any non metal)
Why are metals better conductors than other solids?
Metals contain free electrons which transfer heat quicker than the vibrating atoms.
Alicia lifts a laptop 2m into the air with a force of 10N. How much work does she do?
Force x distance=work done
10N x 2m = 20J
Name 5 energy stores
Chemical stores of energy
Gravitational stores of energy
Kinetic stores of energy
Elastic stores of energy
Thermal stores of energy
If Sophie climbs a ladder 3.4m tall and Sophie has a mass of 48 kg, how much GPE has she gained?
Mass x gravitational field x height = GPE
48kg x 10N/kg x 3.4m = 1632 J
Efficiency = Useful energyx 100
Total energy
An electric motor is used to raise an object. It transfers 60J of useful energy when it is supplied with 200J of electrical energy. Calculate the efficiency of the motor.
60J/200J x 100 = 30%
A motor transfers 60,000 J in 25 secs. What is the power?
Energy/time = power
60,000 J/25 = 2400 W
Usain Bolt has a mass of 85 kg and is running at a steady speed of 10 m/s. How much kinetic energy does he have?
1/2 x mass x velocity2 = KE
1/2 x 85kg x (10m/s)2=4250J
