General useful info Flashcards
What is a vacuum?
A volume that contains no matter
What is the gravitational field strength of the Earth and Moon?
Earth: 9.8N/kg
Moon: 1.6N/kg
What is the speed of sound?
330m/s
What is the speed of light?
300 million m/s (3 x 10^8)
What is the resolution of an instrument?
the smallest increment/change can be read from the equipment (e.g. if ruler measured in mm, the resolution would be 1mm)
How do you calculate uncertainty?
½ x range
What do you call the point where proportionality stops/levels off?
the limit of proportionality
What does it mean to move relative to?
One object will be stationary, the other will move around/in it i.e. relative to it
What is magnetic flux density?
A measure of the strength of the magnetic field
Why do scientists have different models like the wave and particle model of light?
different models may be appropriate in different situations
4 marks
Why do scientists replace an old scientific model with a new one? Give an example
new experimental evidence
evidence cannot be explained using an existing model
new model explains new evidence
e. g. nuclear model of the atom replacing the plum pudding model
* probably removed content*
How can you tell that two variables are in direct proportion from a graph?
The line is straight
and the line passes through the origin
What is thermal radiation?
Transfer of energy by waves
probably removed
When should a line graph be used?
When both variables are continuous
What is a zero error?
(measuring balance) displays reading when no object/mass is on it
(ammeter) displays reading when not connected
