Differences
Type of energy transfer when energy enters a colder object
Endothermic
A force that acts without touching
Non-contact force
When one thing directly causes another
Causation
A graph with a straight line relationship
Linear
A simplified representation of a real system
Model
Another name for potential difference
Voltage
Stored energy due to position in a field
Potential energy
When two variables appear linked, but does not necessarily one thing causes the other
Correlation
A speed–time graph with an increasing line means ______
Faster speed/accelerating
A model using diagrams, maths, or symbols (e.g. computer-generated)
Abstract model
What happens to particle spacing when a substance is heated?
Expand / move apart
In a field diagram, where is the field strongest?
Where the lines are closest together
Jacket sales increase as hot chocolate sales rise.
What is the hidden variable connecting these two statements?
Winter time/cold
In a speed–time graph, a flat, horizontal line means _____
Constant speed, no acceleration
What is a lunar eclipse?
When the Earth is between the Sun and the Moon (SEM); moon appears a reddish colour
Name of the energy needed to change state without temperature change
Latent heat
What is the gravitational potential energy (GPE) of a worker, whose mass is 80 kg, at the top of a skyscraper 300 m above the ground? Take g = 9.8 m/s2
GPE = m × g × h
GPE = 80 × 9.8 × 300
GPE = 235200 J
Correlation or causation:
The cost of living has increased as cellphones have become better
Correlation
How do we know if a graph is a directly proportional graph?
Always goes through (0,0);
if one value doubles, the other value doubles too
Why are scientific models not perfect?
They simplify reality
Density differences, caused by temperature differences, between the sea and land cause _______
Convection currents (sea breeze)
What are three factors affecting gravitational potential energy?
mass, height, gravitational acceleration (force of gravity)
How can scientists identify if a relationship is causation or correlation?
They can carry out experiments and use the results to determine how the changes in variables are related to one another
What does an inversely proportional relationship describe?
If one value increases, another value decreases at a proportional rate
What is the difference between reflection and refraction?
Reflection: the bouncing back of light when it hits a surface
Refraction: the bending of light as it passes from one medium to another