Energy & Speed Flashcards
(14 cards)
What is energy?
Energy is the ability to do work.
What is the unit for energy?
Joules (J)
What are the different types of energy store?
- kinetic
- thermal
- gravitational potential
- chemical
- magnetic
- nuclear
- elastic potential
- electrostatic
What are the different types of energy transfer?
- sound
- electrical
- heat
- mechanical
- light
What work would you do if you pushed a trolley 3m against 100N friction?
The work done would be 300J (joules) or 300N/M (newton-metres).
Energy cannot be _________ or __________.
Energy cannot be created or destroyed.
Energy cannot be created or destroyed, it can only be what?
Energy cannot be created or destroyed, it can only be transferred from one form to another.
What is the difference between useful and wasted energy?
Useful energy is energy that is necessary for the specified process to work and wasted energy is energy that is a side product of the process. It has not been used.
What is the speed, distance, time equation?
Speed (m/s) = distance (m)/time (s)
What is a Sankey diagram?
A Sankey diagram is a diagram with labelled arrows that differ in size dependent on the amount of energy.
What is the efficiency of something in energy terms?
The efficiency of something is the percentage of the energy that it transfers as useful energy.
Where does most of Earth’s energy come from?
The Sun
Fill in the gaps:
Energy is the ability to do ____. Energy cannot be ______ or _________, it can only be ___________ from one form to _______.
Energy is the ability to do work. Energy cannot be created or destroyed, it can only be transferred from one form to another.
For every 100J of energy contained in petrol used by a car, it will transfer 25 J of this energy into kinetic energy. The rest of the fuel is wasted as heat.
How efficient is the car? Explain your answer.
The car is 25% efficient because it uses up 25% of its energy into moving the car and 75% of the energy is wasted.
