Download PowerPoint Chapter 7.2

Work
Work (joules)
Force (N)
W=Fxd
Distance (m)
Work
Key Question:
What happens when you multiply forces in
machines?
Power
Power (watts)
Work (joules)
P =W
t
Time (sec)
Energy


Energy is the ability to do work.
Any object that has energy has the ability to
create force.
 Energy

is measured in the same units as work.
A joule is a unit of force that acts over a
distance.
Potential Energy
Mass (kg)
Potential Energy
(joules)
Ep = mgh
Height (m)
Acceleration
of gravity (m/sec2)
Kinetic Energy
Kinetic Energy
(joules)
Ek = 1 mv2
2
Mass (kg)
Speed (m/sec)
Energy Conservation
Key Question:
What is energy and how
does it behave?
Energy Transformations
Energy transformations
occur between different
types of energy.
— radiant energy
— electrical energy
— chemical energy
— nuclear energy
Energy Transformations
in a Power Plant
Power plants convert
chemical energy into
electrical energy.
1. chemical energy
2. heat energy
3. mechanical energy
4. electrical energy
Energy Transformations
Key Question:
Where did the energy go?