P2H Topic1 Smart Lesson Static and Current Electricity.

Attraction and repulsion repel Positive and positive ________ Negative and negative ________ Positive and negative ________ repel attract Write Down Like charges repel, unlike charges attract.

The structure of the atom ELECTRON – negative, mass nearly nothing PROTON – positive, same mass as neutron (“1”) NEUTRON – neutral, same mass as proton (“1”) 12/11/2018

+ + - - + - + + + - - - + + - + - - Write Down Static electricity is when charge “builds up” on an object and then stays “static”. When two materials are rubbed together the force of friction transfers electrons from one material onto the other material. 12/11/2018 + + - - + - + + + - - - + + - + - - 12/11/2018

Write Down Objects that gain electrons become negatively charged (because they now have more negative charges than positive charges). Objects that lose electrons become positively charged (because they now have more positive charges than negative charges). When two insulators are rubbed together they equal sized but opposite charges.

Write Down Dangers of Charge Fuel filling, paper rollers and grain shoots are all charge problems. As the fuel flows along the pipe or paper rolls over rollers or grain shoots out of tubes, friction causes static to build up. This can easily lead to a spark and then an explosion. To prevent this happening, the nozzles or rollers are made out of metal so any charge build up is conducted away. Large petrol tankers always have earthing straps between the tanker and the storage tank to prevent the risk of sparks.

Transferring flammable liquids What prevents large static charges building up that could cause a possible explosion? nozzle from tanker underground tank or aeroplane tank. electrical link

Static Electricity in Lightning 12/11/2018

Charge, current and time Write Down Charge = Current x time Charge measured in Coulombs (C) Current measured in Amps (A) Time measured in seconds (s) Q T I

A current of 6A flows for 3 minutes. How much charge flows? Charge = Current x time = 6A x (3x60)s = 1080 C Always convert time to seconds!!!

P2H Topic2 Smart Lesson Current Electricity and Resistance.

Words: volts, amps, ohms, voltage, ammeter, voltmeter Basic ideas… 12/11/2018 12/11/2018 Electric current is when electrons start to flow around a circuit. We use an _________ to measure it and it is measured in ____. Potential difference (also called _______) is how big the push on the electrons is. We use a ________ to measure it and it is measured in ______. Resistance is anything that resists an electric current. It is measured in _____. Words: volts, amps, ohms, voltage, ammeter, voltmeter

Ammeters and Volmeters Write Down Ammeters and Volmeters Ammeters are placed in series to measure current. Voltmeters are placed in parallel to measure voltage.

Current and Voltage Meanings. 12/11/2018 Write Down By definition, current is “the rate of flow of charge”

Resistance V R I Resistance = Voltage (in V) (in ) Current (in A) Georg Simon Ohm 1789-1854 12/11/2018 12/11/2018 Resistance is anything that will RESIST a current. It is measured in Ohms, a unit named after me. The resistance of a component can be calculated using Ohm’s Law: V R I Resistance = Voltage (in V) (in ) Current (in A)

Understanding Resistance 12/11/2018 When a voltage is applied it basically causes electrons to move towards the positive end of the battery: Electrons Ions Negative Positive Write Down The metal ions in a conductor vibrate and get in the way of the electrons – this is resistance. This effect causes the metal to heat up.

Power = voltage x current Electrical Power 12/11/2018 Write Down Power is defined as “the rate of transferring energy” (i.e. how much energy is transferred in one second) and is measured in units called “Watts” (W). The amount of power being transferred in an electrical device is given by: P I V Power = voltage x current in W in V in A

Write Down 12/11/2018 12/11/2018 1) Light dependant resistor – resistance DECREASES when light intensity INCREASES 2) Thermistor – resistance DECREASES when temperature INCREASES Resistance Amount of light Resistance Temperature

P2H Topic3 Smart Lesson Forces and Acceleration.

Vector vs. scalar Write Down 12/11/2018 Write Down Scalar quantities have size (“magnitude”) only and no direction. Vector quantities have both size and direction. Scalar or vector??? Scalar Vector 2. Distance 10. Acceleration 1. Mass 6. Energy 7. Time 3. Displacement 4. Speed 9. Force 8. Current 5. Velocity

Summary Write Down Complete these sentences… 12/11/2018 12/11/2018 Complete these sentences… If an object is stationary and has NO resultant force on it the object will… If an object is stationary and a resultant force acts on it the object will… If an object is already moving and NO resultant force acts on it the object will… If an object is already moving and a resultant force acts on it the object will… …accelerate in the direction of the resultant force …continue to move at the same speed and the same direction …continue to stay stationary …accelerate in the direction of the resultant force

Acceleration V-U T A Tip: 12/11/2018 12/11/2018 V-U T A Acceleration Acceleration = change in velocity (in m/s) (in m/s2) time taken (in s) Tip: Make sure you learn the units for acceleration.

Force and acceleration 12/11/2018 12/11/2018 If the forces acting on an object are unbalanced then the object will accelerate. Force (in N) = Mass (in kg) x Acceleration (in m/s2) F A M