physics Flashcards
What are the two categories of energy?
Potential & kinetic
Identify types of potential energy (5)
gravitational, elastic, electric, chemical, nuclear
Identify types of kinetic energy
kinetic, thermal
state the law of conservation of energy
energy cannot be created or destroyed, only transferred
what is an electrical current?
flow of charged particles
how does a current flow through a circuit?
a power source creates voltage that pushes electrons through the circuit
what is voltage?
The change in potential energy
identify components that make up a circuit
power source: provides energy
wires: connect components, flow of current
load: resistor, light bulb, motor - consumes energy
switch: can open or close a circuit
what is current?
the amount of charge passing a point each second OR the energy being transferred to or from an electron.
what is resistance?
The ratio of the voltage across a component, to the amount of current that will pass through
How does resistance affect the flow of a current?
when the resistance is increased, the current has less energy
what is the relationship between voltage, current & resistance? (Ohm’s law)
V = IxR
R = V/I
I = V/R
difference between series and parallel circuits
parallel circuit → each electron travels down only one paths and transfers all its energy there, the current splits into 2 paths
series circuit → the total voltage drop across all components is equal to the voltage supplied by the power supply, because each electrons passes through energy component and shares its energy transfers, the current is the same every where
Identify the formula for resistance in a series circuit
All the resistance added up together
Identify the formula for resistance in a parallel circuit
1/resistance total = 1/R1 + 1/R2 + 1/R3 …
define dissipation of energy
The process where energy is transformed into forms that are less useful (heat, light, sound, etc). In electrical circuits, dissipation is the conversion of electrical energy into heat due to the resistance of materials.
define motion
Motion is the change in the position of an object with respect to time
define energy
the ability to do work
Identify the difference between distance and displacement
distance: magnitude, scalar
displacement: magnitude, direction, vector
describe how forces cause motion
Forces are the causes of motion and changes in motion. forces can cause an object to start moving, stop moving, or change direction. They can also alter the speed or shape of an object in motion. Forces are responsible for accelerating objects.
Describe how the slope of a distance time graph indicates the speed of an object
steeper slope = higher speed.
flatter slope = lower speed.
horizontal line = object is at rest.
Identify the difference between speed and velocity
speed: the rate at which an object moves, magnitude, scalar
velocity: rate at which an object moves in a specific direction, magnitude, direction, vector
speed, distance, time equation
Distance = speed x time
Time = distance/speed
Speed = distance travelled/time taken
Average speed = d2 - d1 / t2 - t1
Define acceleration and identify the units used for acceleration
The rate of change of velocity
m/s/s
acceleration formula
a = vf - vi /tf - ti
Newtons first law of motion
An object will keep moving with the same velocity unless acted on by a net force. (this is due to inertia)
what is intertia
inertia is the tendency of an object to maintain its current motion without change
newtons third law of motion
Every force has an equal & opposite reaction force
newtons second law of motion
The net force of an object is equal to its mass multiplied u its acceleration
F = ma (N = kg x m/s/s)
