Physics Gcse Flashcards
What is velocity?
Speed in given direction
What is acceleration?
Change I’m velocity - could mean change of speed
What is deceleration?
Negative acceleration
What happens when you accelerate around a corner?
If you maintain the same speed you will be accelerating as your direction is changing
How do you work out acceleration?
Change in velocity/time taken
Or
Final velocity-initial velocity/time taken
What is drag?
Caused by forces which oppose the motion of an object
How is air resistance caused?
Colliding air particles that they’re trying to go through
3 ways a cars drag can be reduced?
Aerodynamics
Weight
Speed
What is the stopping distance?
Time taken between becoming aware of need to stop and stopping
What is thinking distance?
Becoming aware of need to stop and moving foot to break
What is breaking distance?
Distance between putting foot on break and actually stopping
What is mass?
Amount of matter/atoms an object has
What is mass measured in?
Kg
What is weight?
The force an object feels due to gravity
e.g. Astronauts say they feel weightless but they still have the same mass
The bigger the mass…
…the higher the the gravity
How to calculate weight?
Weight = mass x gravity
What is work done?
Energy transferred during a process
How to work out work done?
Force x distance moved in direction of force
What is power?
How quickly energy is transferred
What happens when energy is transferred quickly?
High power
What happens when energy is transferred slowly?
Low power
Ways to reduce energy?
Install boiler - expensive, saves most = 6.5 years to pay
Install double glazing - most expensive, saves least = £120
Install wall insulation - cheap = 2 years and 9 months to pay
Install loft insulator - short payback time = 2 years
Types of energy?
Magnetic Kinetic Heat Light Gravitational potential energy Chemical Sound Electric Elastic potential Nuclear
What is gravitational potential energy?
Energy stored in an object in a g.p. field
How to work out gravitational potential energy?
Mass x g.field x height
How to work out momentum?
Mass x velocity
What’s the law of conservation of momentum?
Momentum before an event must be equal to momentum after
What is flow of electrons called?
Current
How is current measured?
With an ammeter, how fast negative charge flows around the circuit
What is an analogy?
Compare on situation to the other and understand idea as accurately as possible
What is Ohm’s Law?
Potential difference = current x resistance
How does p.d. behave in a series circuit?
P.d. gained by cells is divided between two components
How does current behave in a series circuit?
All current is equal in all parts
What happens in a parallel circuit?
Current splits between each branch
What happens to the resistance when the temp of a resistor increases?
Atoms vibrate more
What is the earth wire (g+y)?
Transfers energy away from device if there’s a fault
What is the neutral wire (blue)?
Completes circuit and has p.d. of 0V
What is the live wire (brown)?
Provides energy to device - p.d. = 230V
Why is copper good for wires?
Good conductor
Malleable
Won’t retract when bent
Why is brass good for pins?
Good conductor
Harder than copper
Does not corrode
How do you work out power?
Energy/time
Or
Current x p.d.
