Energy Stores and Transfers

Question 1

What is a system and what happens when a system changes ?

Answer 1

-an object or a group of objects
-if it changes, there are changes in the way energy is stored
Eg, rollercoasters, go between gravitational and kinetic energy

Question 2

What type of diagram shows the way energy is redistributed when a system is changed ?

Answer 2

-SANKEY DIAGRAM

Question 3

Equations for kinetic energy ?

Answer 3

1/2mv^2

(0.5 x mass x [speed squared])

Kinetic = Joules (J)
Mass = Kg
Speed = m/s

Question 4

Equations for gravitational potential energy

Answer 4

mgh

(Mass x gravitational field strength x height)

GFS = N/kg
Height= m

Question 5

Equation for elastic potential energy

Answer 5

1/2ke^2

(0.5 x spring constant x {extension squared})

Spring constant = N/m
Extension = m

Question 6

What is internal energy ?

Answer 6

Total kinetic and potential energy of all particles that make up a system

Question 7

If you increase the work on a system, what does it do to the energy ?

Answer 7

Increases energy STORED in system

Question 8

How does heating change the energy stored in a system ?

Answer 8

-increases energy of particles within it, as energy increases, it will increase the temp or produce a change of state

Question 9

If temp increases, the increase depends on :

Answer 9

• mass on substance heated
• what substance is
• energy input

Question 10

What is specific heat capacity ?

Answer 10

Amount of energy required to raise he temp of one kilogram of the substance by one degree Celsius

Question 11

What is the equation for change in thermal energy ?

Answer 11

-mass x specific heat capacity x temp change