Bell Ringer
• A book weighing 1.0 newton is lifted 2 meters.
How much work was done?
• A force of 15 newtons is used to push a box
along the floor a distance of 3 meters. How
much work was done?
Assignment
• Pick one of the following people: Benjamin
Franklin, Alexander Graham Bell, Eli Whitney,
James Watt, Thomas Edison, Guglielmo
Marconi, Michael Faraday, the Wright
brothers, Charles Babbage
• Make a list of inventions for this person
• Pick one invention, draw a simple picture of it,
and tell how it worked.
• What types of simple machines did it have?
Energy
• Energy is defined as the capacity to do work.
• Whenever work is done, energy is
transformed from one system to another.
• Energy is measured in Joules.
Potential Energy
• Potential Energy (PE) is called the energy of
position because it results from the relative
positions of objects in a system.
• A stretched rubber band has PE.
• Gravitational Potential Energy- depends on
the mass of the object and its height relative
to Earth’s surface.
Kinetic Energy
• Kinetic energy (KE) is the energy of the object
due to its motion.
• KE depends on mass… a bowling ball can do
more work than a tennis ball when moving at
the same speed.
• Atoms and molecules have kinetic energy
Mechanical Energy
• Mechanical energy is the amount of work an
object can do because of its kinetic and
potential energy.