Physics 1 - Energy and Energy resources (P1 - P3)

Question 1

What is a closed system?

Answer 1

An isolated system in which no energy transfers take place out of or into the energy stores of the system.

Question 2

What is the equation for work done (energy transferred)?

Answer 2

Work done (Joules J) = Force applied F (Newtons N) x Distance moved along the line of action of the force S (Metres m)

Question 3

What is the equation for change in an object’s gravitational potential store?

Answer 3

Change in G.P.E store (J) = Weight (N) x Change of Height (m)

Question 4

What is the equation for change in G.P.E store?

Answer 4

Change in G.P.E store (J) = Mass (Kg) x Gravitational field strength (N/Kg) x Change of height (Metres m)

Question 5

What is the equation for kinetic energy?

Answer 5

Kinetic energy (Joules J) = 0.5 x mass (Kg) x speed2 (m/s squared)

Question 6

What is the equation of efficiency of a device?

Answer 6

Efficiency = Useful output energy (J) / Total input energy energy (J) (x 100 for percentage)

Question 7

What is power?

Answer 7

Rate of transfer of energy

Question 8

What is the equation of power?

Answer 8

Power (watts W) = Energy transferred to appliance (Joules J) / Time taken (Seconds s)

Question 9

What radiation is emitted from the sun?

Answer 9

Infrared

Question 10

What is the equation for specific heat capacity?

Answer 10

Energy transferred (Joules J) = Mass (Kg) x SH capacity (J/Kg per degree celsius) x Temp change (degree Celsius)

Question 11

What is the specific heat capacity?

Answer 11

The energy needed to change the temperature of 1kg of the substance by 1 degree celsius.

Question 12

What is a biofuel + example?

Answer 12

Renewable sources of energy. Biofuels such as methane and ehtanol can be used to generate electricity.

Question 13

What is the equation for gravitational potential energy?

Answer 13

G.P.E = Mass (Kg) x Gravitational field strength x Height (m)