11 PHYSIC Flashcards
(22 cards)
Define speed
Rate of change of distance
Vector + examples
Physical quantity with size and direction
(displacement, velocity, weight)
Scalar + examples
Physical quantity with size only
(distance, speed, mass)
Acceleration
Rate of change velocity
Force
The push or pull on an object (N)
Mass Vs Weight
MASS is the amount of matter that makes us an object whereas WEIGHT is the force which gravity pulls something towards the earth.
Pressure
Is a measure of force applied to a particular area. (Pa pascals)
Gravitational potential energy
Energy stored in an object due to height above earth. (Joules J )
Kinetic energy
Energy in an object due to its motion (Joules J )
Work
Force(s) move an object, results in transfer of energy to object. (Joules J )
Power
The rate of doing work (Watts W)
Conductor
Substances that allow electrons to flow freely through them. e.g. metal
Insulator
Substances that do not allow electrons to flow freely through them. e.g. plastic
resistance
Measure of how much an electrical component opposes the flow of current. (Ohms)
Current
Amount of charge passing a point per second (Amps A)
Voltage
Difference in energy per coulomb between 2 parts of a circuit. (Volts V)
Advantage of parallel circuits over series
If something breaks in a series circuit the whole thing will stop working due to their only being one pathway whereas in a parallel circuit if something breaks only that particular loop will be affected and others will still work.
How voltage, current resistance and power change in a SERIES CIRCUIT when components are added or removed.
- Current is the same at every point
- Voltage is divided among components
- Resistance adds in a loop - more components added makes it more difficult for current to flow.
- More lamps in circuit, decrease in brightness as voltage is shared.
How voltage, current resistance and power change in a PARALLEL CIRCUIT when components are added or removed.
- Current splits through loops
- Voltage is the same in each loop
- Resistance decreases with more loops - more pathways makes it easier for current to flow.
- More lamps in parallel, brightness of the bulbs stays the same.
Static electricity
Electrostatic forces between charge particles cause movements of these charged particles.
Electric fields
- positive arrows go away from the centre
- negative arrows go towards the centre
- Positive arrows point towards negative
- like forces repel
- unlike forces attract
Newtons 2nd law of motion
Force = mass x gravity
- If there is net force on object, it ALWAYS accelerates
- Acceleration is always proportional to the force applied
- And is inversely proportional to the object’s MASS
