Post on 02-Dec-2014
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Who am I?
FUNCAU!
Formula FrenzyAtoms and Matter Lesson 3
Learning Intention To learn to recognise and manipulate
formulas
Using Symbols When quantities are put into formulas as
unknowns we give them a symbol. We use the same symbol to keep track of what we are doing.
Some are easier to remember than others…
quantity symbol
Distance dTime tSpeed vDisplacement sVelocity vacceleration a
quantity symbol
Charge
Current
Voltage
Power
quantity symbol
Charge QCurrent I
Voltage VPower P
In formulas we replace the quantity with the symbol
quantity symbol
Distance dTime tSpeed vDisplacement sVelocity vacceleration a
d
v x t
formulas
quantity symbol
Distance dTime tSpeed vDisplacement sVelocity vacceleration aInitial velocity uFinal velocity v
d
v x t
formulas
The symbol Δ (delta) means “change of”
In these formulas a is the subject
Worked example
1. If a sprinter reaches 12 m/s in 3 seconds what is his acceleration?
V=12m/sU=0 m/st= 3 sa = ? a= 12 – 0
3a = 4 m/s/s = 4 m/s2
What about me?
For Formula Questions always follow FUNCAU
F – write formulaU – write down the
unitsN – sub in the numbersC – do the calculationsA- write answerU – add the units
FormulasLets change the subject
What techniques
and skills do I need?
• To “read” it. These are not just numbers they mean something.
• What techniques can we use to “read” it?
FormulasLets change the subject
What techniques
and skills do I need?
• Understand order of operations
• BODMAS• BOMDAS• BEDMAS• WHATEVER
FormulasLets change the subject to u
A car is travelling at 10m/s and increases to 20m/s in 4 seconds what is it’s acceleration?
If that acceleration continues what will it’s speed be 3 seconds later?
UseE=mcΔT
to work out the energy required to raise the temperature of 2kg of water by 10oC.Cwater = 4200 J/kgoCHow much water could you boil if you used 10kJ?