Physics Test (Year 8) Flashcards
How do you calculate power?
power (w) =
energy (j)
________
time (s)
How do you calculate the work done?
work done (j) =
force (N) x distance (m)
What does the speed, distance, time triangle look like?
/ D \
/ S | T \
______
How do you calculate pressure?
pressure (N/m²) =
force (N)
________
area (m²)
How do you calculate the moment (turning force)?
moment (Nm) =
force (N) x distance from pivot (m)
How do you calculate current?
current (A) =
potential difference (v)
_________________
resistance (Ω)
How do you calculate resistance?
resistance (Ω) =
potential difference (v)
_________________
current (A)
What does the resistance, potential difference and current triangle look like?
/ V \
/ A | R \
______
You are driving a car at 60mph. Another car is travelling in the same direction as you at the same speed.
What is the relative speed?
0
Two cars are moving at each other at 30mph.
What is the relative speed?
60mph
What charge do protons have?
Positive
What charge do electrons have?
Negative
What charge do neutrons have?
They have no charge.
What is an electric field?
A region where a charged material or particle experiences a force.
What is potential difference?
A measure of the push of a cell or battery, or the energy that the cell or battery can supply.
How can energy be transferred?
Through:
Conduction
Convection
Radiation
What is conduction?
The way in which energy is transferred through solids, and to a much lesser extent in liquids and gases.
What is convection?
The transfer of energy by the movement of heated liquids or gasses.
What is radiation?
The transfer of energy as a wave.
What happens when you heat a solid?
The particles vibrate more.
What happens when you heat a liquid or a gas?
The particles move faster and vibrate more.
Explain the law of conservation of energy.
Energy cannot be created or destroyed, only transferred.
Explain the law of moments.
An object is in equilibrium if the clockwise moments equal the anticlockwise moments.
What piece of equipment is used to measure potential difference?
Voltmeter
In a series circuit which is the same for each component?
Current
How can you increase the strength of an electromagnet?
Increase the current
Increase the number of turns
Add an iron core
Define current.
Current is the flow of charge.
What piece of equipment is used to measure current?
Ammeter
Define potential difference.
A measure of the push of a cell or battery or the energy that the cell can supply.
Give the unit for potential difference.
Volts
v
Give the unit for current.
Amperes or Amps.
A
What pieces of equipment would you need to investigate a magnetic field?
A bar magnet, plotting compasses or iron filings and some paper.
How do you calculate the relative motion/velocity?
Object A speed - Object B speed
How do you calculate the relative motion/velocity if the objects are travelling in opposite directions?
Object A speed - (-Object B speed)
