end of year (y9 and y10 content) Flashcards
what is the equation for average speed?
average speed= distance moved/time taken
what is the equation linking acceleration, change in velocity and time?
acceleration=change in velocity/time taken
a=v-u/t
what are the effects of forces between bodies?
forces can:
- change the shape of an object
- change the speed of an object
- change the direction of an object
what are vector quantities and scalar quantities and how do they vary from each other?
Vector quantities have both magnitude and an associated direction. This makes them different from scalar quantities, which just have magnitude.
what type of quantity is force?
force is a vector quantity
what is friction?
a force that opposes motion
what is the equation that links force, mass and acceleration?
force = mass x acceleration
f = m x a
what is the equation that links weight, mass and gravitational field strength?
weight = mass x gravitational field strength
w = m x g
what is the stopping distance of a vehicle?
the stopping distance of a vehicle is made up of the sum of the thinking distance and the braking distance.
what are the factors affecting the stopping distance of a vehicle?
- speed of vehicle
- mass of vehicle
- road conditions and type
- reaction time
what does a current in a resistor result in?
how can this be used in a variety of domestic contexts?
- the electrical transfer of energy
- increase in temperature
Resistance causes transfer of electrical energy to heat energy. Some components are designed to have a high resistance to make sure this happens, for example electrical heaters that have lots of resistors to ensure a high resistance so a lot of heat is produced.
what is the equation linking power, current and voltage?
power = current x voltage
P = I x V
what is the equation linking energy transferred, current, voltage and time?
energy transferred = current x voltage x time
E = I x V x t
why is a series or parallel circuit more appropriate for particular applications?
Parallel circuits are useful if you want components to continue to work, even if one component has failed. This is why our homes are wired up with parallel circuits.
Eg. Christmas tree lights, household lighting system
Series circuits are useful if you want a warning that one of the components in the circuit has failed. They also use less wiring than parallel circuits.
Eg. flashlights, fridges
how is the current in a series circuit affected?
- applied voltage
- number of other components
- nature of other components
what is the equation linking voltage, current and resistance?
voltage = current x resistance
V = I x R
what is current?
the rate of flow of charge
what is the equation linking charge, current and time?
charge = current x time
Q = I x t
what is electric current in solid metallic conductors?
a flow of negatively charged electrons
why is current conserved at a junction in a circuit?
The total amount of current flowing into the junction is equal to the total current flowing out. This is because current is conserved as no charge has been gained or lost.
what is the voltage?
the energy transferred per unit charge passed
what is a volt?
a joule per coulomb
what is the equation linking energy transferred, charge and voltage?
energy transferred = charge x voltage
E = Q x V
identify some common materials which are electrical conductors or insulators, including metals and plastics
good:
- copper
- aluminium
- steel
- gold
bad:
- plastic
- glass
- wood
- marble
