When a lightbulb warms up what is the wasted energy?
Question 3
3.
How could you reduce the amount of air resistance acting on an object?
Question 4
4.
Which equipment would you use to measure 93ml of water?
Question 5
5.
A child runs 1200m in 260 seconds. What is their speed?
Question 6
6.
Challenge: name the 8 energy stores.
Key Knowledge: LCWC
Question 7
7.
Define Efficiency
Question 8
8.
State the equation used to calculate efficiency
Question 9
9.
Name the two ways efficiency can be written
Question 10
10.
Name the energy transferred to the surroundings
Recall Quiz
Question 11
11.
What is the correct definition of efficiency?
Question 12
12.
State the equation used to calculate efficiency
Question 13
13.
If a kettle has an efficiency of 0.875, what is this efficiency written as a percentage?
Question 14
14.
When energy has been transferred to the surroundings it has…
I do
Question 15
15.
400 Joules of energy goes in and 350 Joules is transferred to thermal energy therefore only ………….. Joules of sound is wasted
You do
Question 16
16.
10,000 Joules of kinetic energy goes in and 8,000 Joules of energy is transferred to electrical and therefore only ……………Joules of heat energy is dissipated.
I Do
Question 17
17.
Calculate the efficiency, as a percentage, of a speaker that uses 300 J which it radiates as 96 J of sound energy.
We Do
Question 18
18.
100J of energy is transferred electrically to a filament bulb, of which 45J are radiated usefully as light. Calculate its efficiency as a percentage.
You Do
Question 19
19.
250J of energy is transferred electrically to a filament bulb, of which 150J are radiated as light and 100J stored thermally in the filament. Calculate its efficiency as a percentage.
Challenge
Question 20
20.
2.5kJ of energy is transferred electrically to a filament bulb. The efficiency of the lamp is 0.4. Calculate how much energy is usefully transferred
Plenary
Question 21
21.
To calculate efficiency you divide ________ by __________.
Question 22
22.
If an energy transfer is very efficient that means that a (large/small) amount of energy is being transferred usefully & a (large/small) amount is dissipated.
Question 23
23.
3)If a transfer has an efficiency of 0.75, we can also write this as being ___________% efficient.