Please enable JavaScript.
Coggle requires JavaScript to display documents.
Work, energy and power(Benjamin) (P2.4 Energy resources (Solar panels…
Work, energy and power(Benjamin)
P2.2 Energy
-
If an object is upward, it has gravitational energy
-
-
An electric current is a good way of transferring energy from one place to another. It carries electrical energy
-
If there is a rubber band, it becomes a store of strain energyor elastic energy
-
If there is a hot object, there are thermal(heat) energy coming from it
Very hot objects glow brightly, they are givng out light energy
-
Some energy is also transferred as infrared and ultraviolet radiation. These are all forms of electromagnetic waves
P2.1 Work and P2.3 power
-
When energy is transferred from one object to another by means of a force, we say that the force is doing work
-
joule: one joule (1J) is the energy transferred (or the work done) by a force of one newton (1N) when it moves through a distance of one metre (1m) in the direction of the force
-
Power: the rate at which work is done, or the rate at which energy is transferred
-
-
P2.4 Energy resources
-
-
-
-
-
-
-
-
Cost
We should separate initial costs from running costs. A solar cell is expensive to buy but there are no costs for fuels-sunlight is free!
Reliability
The wind is variable, so wind power is unreliable. Wars and trade disputes can interrupt fuel supplies
Scale
A fossil-fuel power station can be compact and still supply a large population. It would take several square metres of solar cells to supply a small household
Environmental impact
The use of fossil fuels leads to climate change. A hydroelectricity dam may flood useful farmland. Every energy source has some effect on the environment
-
-