1.1 energy changes in a system Flashcards
1
Q
Define the ‘Specific Heat Capacity’ of a
substance.
A
The amount of energy needed to raise the temperature of 1 kilogram of a substance by 1 degree Celsius.
2
Q
What is the definition of ‘Power’?
A
The rate at which energy is transferred
3
Q
Two motors lift the same mass through the same height. Motor A does this in half the time of Motor B. Which dissipates the most power?
A
Motor A.
The energy transferred is the same but the time taken is less
4
Q
Explain why a bungee jumper slows down once the cord begins to stretch.
A
● Kinetic energy decreases since it is converted to elastic potential energy
● Since KE is proportional to (velocity)², as KE decreases, so does velocity.
5
Q
Give examples of chemical energy stores.
A
● Food
● Fuel (eg. wood, coal, petrol)
● Batteries
