Extras Flashcards
What do simple levers make it easier to do
Easier to do work by moving the distance the force is applied further from the pivot
Where are pendulums used
Clocks, playground swings, fairground rides
What is cross section area in a hydraulic measured in
M^2
What is velocity
Both the speed and direction of an object
Example of a centripetal force using friction
A car going round a bend.
Friction between the cars tyres and the road
What can magnetic fields be represented by
Field diagrams - the arrows on them always pint from North Pole to the South Pole
What is a magnetic field made up of
Concentrated circles with the wire in the centre
How to work out which way the magnetic field is going around a wire
The right hand thumb rule where you curl your hand and your thumb points the way of the current and the direction your fingers are curled shows the direction of the field
How can you increase the strength of the magnetic field around a coil of wire (a solenoid)
Adding a magnetically soft iron core through the middle of the coil (an electromagnet is formed)
What are electromagnets used in
Electric bells, car ignition circuits and some security doors
What way does current flow usually
From +ve to -ve
What does electric motors use the motor effect for
To get them and keep them moving
How do electric motors help make CD players, food mixers, fan heaters, fans, printers, drills, hair dryers, cement mixers work
Link the coil to an axle and the axle spins round.
This can be attached to a fan, a blade or whisk, the bit you sit the cd on.
Fan heaters and hair dryers have an electric heater as well as a fan.
Why will a freely suspended object swing until it’s centre of mass is vertically below the point of suspension
Objects weight acts at a distance from the pivot which creates a moment around the pivot so it swings.
Until centre of mass is at its lowest then it rests in this position because there’s no moment.
The pivot is in line with the line of action of the force.
What is the wiring to a three pun plug
- the right coloured wire is connected to each pin and firmly screwed
- no bare wires in the plug
- cable grip tightly fastened over the cable outer layer
- depending on the appliance have the right cable size because thicker cables have less resistance so they carry more current
Why are parts of the plug made of metal like copper and brass
Because they are good conductors
What are two important effects of gravity
Gives everything a weight
Makes everything accelerate towards the ground
What is weight measured using
A sprint balance or Newton metre as its in newtons
What is mass measured using
A mass balance as its in Kg
What is the gravity on the moon
1.6 N/kg
What is an example of a circuit breaker
Residual current circuit breaker
RCCB
How do RCCBs operate
Detecting a different in he current between the live and neutral wire
If an appliance is double insulated what does this mean
It has no earth wire connection - only metal cased ones do