Physics Flashcards
What is current and what is its unit of measurement?
Current measures the rate electrons flow past a point. Measured in amps (A)
What is voltage and what is it measured in?
Voltage is the difference in energy between 2 parts of a circuit. Measured in volts (V)
How does current act in a series circuit?
Current stays the same all the way around
How does voltage act in a series circuit?
Voltage is shared around the circuit and adds up to the voltage of the power supply.
How does current behave in a parallel circuit
Current is shared between each branch
How does voltage behave in a parallel circuit?
Voltage stays the same on each branch
What is ohms law?
V=IR
Voltage=current (times) resistance
(V). (A). (Ohms)
Electric current is directly proportional to voltage
How do you calculate the weight of an object using its mass and the value of g=10
W=mg
What is a lever?
A simple machine which uses a pivot
How do you calculate a moment?
Moment=force (times) perpendicular distance
Nm. N. M
How do you make it easier to carry a mass?
Hold it the furthest away possible from the pivot because less effort is needed that way
What can forces do to an object
Change the shape of an object
Change the direction of an object
Change the speed of an object
What else can force do?
It can compress an object or stretch it
What is hooke’s law?
Force=spring constant (times) extension
N. N/cm. cm.
What is a elastic material
An elastic object is one that when the load is removed, it returns to its original shape
How do you calculate density?
Density=mass
Volume
What is density measured in?
Kg/m3 OR G/cm3
What is heat transfer
The flow of heat energy from hot to cold areas
What is conduction?
The transfer of heat particles between different solids
How does heat transfer work in terms of conduction?
Heat transfers from one solid to the other by neighbouring particles colliding into one another
How does heat transfer work in terms of convection?
Heat passes from one liquid to gas, vis versa
1)particles gain energy
2)so they move faster
3)so they spread out
4)so they are less dense
5)so they float up
How do you describe heat transfer in terms of radiation?
Energy is transferred by electromagnetic waves
Radiation has 2 possible outcomes it can be absorbed or reflected
How does evaporation work?
When it gets slightly hot the water particles expand, spreading out, and then rising up making the water ‘disappear’ into the atmosphere
How does heat transfer work in terms of radiation?
It occurs via electromagnetic waves
