Energy Transfer Flashcards
Global warming may lead to ‘higher maximum temperatures and more hot days over all land areas.’ Give examples of four possible consequences of this change.
- Draught
- Poor crops, lack of food
- Increased spread of disease
- Rivers dry up
- Ice caps melt
A bicycle has a kinetic energy of 124J. What kinetic energy would the bicycle have if it had twice the mass but was moving at the same speed?
248J
A bicycle has a kinetic energy of 124J. What kinetic energy would the bicycle have if it had half the mass and was moving at twice the speed?
248J
Power (Watts) =
Power (Watts) = work done (J) / time taken (s)
A Watt is the standard metric of work. True or false?
False, Watt is the unit for power, Joule is for energy
Ceres is the largest and most massive asteroid in the asteroid belt, having an estimated mass of 3 x 10^21 kg and an orbital speed of 17900m/s. Determine the amount of kinetic energy.
4.8 x 10^29
Lost disadvantages of renewable energy resources
- Unsightly
- Disrupt habitats
- Expensive to maintain
- Sometime hard to access
- Small output
- Dependant on the weather
If person A and person B do the same job but person B does it faster, then person A does more work but person B has more power. True or false?
False, if two people do the same job, then they’re doing the same amount of work. The person who does it fastest generates more power.
What are the energy transfers involved in generating electricity using nuclear power?
Nuclear (Uranium) -> Kinetic (products of fission) -> Thermal (friction of movement) -> Thermal (coolant) -> Thermal (boiler) -> Kinetic (steam) -> Kinetic (turbine) -> Electrical (generator)
In a fossil fuel power station energy is released by _______ the fossil fuel (coal etc)
Burning
Global warming may lead to ‘more intense precipitation events (rain, snow hail).’ Give examples of four possible consequences of this change.
- Flooding
- Loss of land for living / growing crops
- Famine
- Spread of disease
What are the energy transfers involved in generating electricity using water?
GPE (water at top of waterfall) -> Kinetic (turbine) -> Electrical (generator)
List advantages of non renewable energy resources
- Cheap to run
- Reliable
- High output
What are the energy transfers involved in generating electricity using geothermal?
Thermal (ground) -> Thermal (water) -> Kinetic (steam) -> Kinetic (turbine) -> Electrical (generator)
Fossil fuel power stations release lots of _____ _____ as a waste product. This is a ____ gas.
Carbon dioxide
Greenhouse
What is the equation for the efficiency of an appliance?
Efficiency = useful energy output
————————–
total energy input
What is the unit for work?
Joules, J
What are the energy transfers involved in generating electricity using fossil fuels?
Chemical potential energy (coal) -> Thermal (furnace) -> Kinetic (steam) -> Kinetic (turbine) -> Electrical (generator)
What is the equation used to calculate the energy transferred when a device is turned on?
Energy transferred or work done = Power x Time
List disadvantages of nuclear energy
- Dangerous if goes wrong
- Radioactive waste needs safe storage for thousands of years
What are the energy transfers involved in generating electricity using solar cells?
Light (sun) -> Electric (cells)
Nuclear power stations produce ______ waste
Radioactive
Calculate the work done by a man pushing a car 25m along a road if he pushes with a force of 600N
Work done = Force x Distance
15000J
An 800N man climbs 5m up a ladder. How much gravitational potential energy does he gain?
4000J
Energy is never _____ nor _____ but is always ______
Created nor destroyed
Conserved
A flowerpot weighing 5N falls off a windowsill 10m above the ground. What is its kinetic energy just before it hits the ground? What is the average speed as it falls?
50J
14.14m/s
What are the energy transfers involved in generating electricity using solar heating?
Thermal (sun) -> Thermal (water)
List disadvantages of non renewable energy resources
- Running out
- Mining disrupts habitats
- Polluting (greenhouse gases, acid rain)
Power is the rate of
Energy transfer (or doing work)
List advantages of renewable energy resources
- No polluting gases
- Free resources
- Will not run out of wind or waves!
List the nine forms of energy
- Thermal
- Light
- Sound
- Kinetic
- Electrical
- Chemical
- Nuclear
- Elastic potential
- Gravitational potential
What is the kinetic energy of a 2kg dog running at 6m/s?
36J
List advantages of nuclear energy
- Relatively cheap to run
- No polluting gases
- High output
Some people apply a cumulative force of 1080N to push the car 218m to the nearest fuel station. Determine the work done on the car
235000J
A motor exerts an average force of 890N to push large crates a distance of 12 meters in 22 seconds. Determine the power output required of such a motor. (Find work done first)
485W
A bicycle has a kinetic energy of 124J. What kinetic energy would the bike have if it had the same mass and was moving with half the speed?
31J
A bicycle has a kinetic energy of 124J. What kinetic energy would the bike have if it had twice the mass and was moving with twice the speed?
496J
A bicycle has a kinetic energy of 124J. What kinetic energy would it have if it had three times the mass and was moving at half the speed?
93J
What is the gravitational field strength on Earth?
10N/kg
Determine the work done in dead lifting 300kg to a height of 0.9m above the ground
2700J
What are the energy transfers involved in generating electricity using wind?
Kinetic (wind) -> Kinetic (blades) -> Electrical (generator)
