Download Kinetic and Potential Energy

Kinetic and Potential Energy
Examples and Situations
Changes in Potential Energy
• Reminder PE = mgh
• The amount of potential energy (PE) will
increase if the mass (m) or height (h) increases
• The amount of PE will then decrease as the
mass (m) or height (h) decreases
Example of changes in potential
energy
• Put the spheres in order of greatest to least amount of
potential energy
• All of the spheres have the same mass
B
C
A
Results
• The order of most to least potential energy is
letter B has the most, then C and then A.
B
C
A
Changes in Kinetic Energy
• Reminder the formula for kinetic energy is
KE = ½ mv2
• Reminder that kinetic energy is the energy of
motion
• This type of energy is affected by mass and
velocity
Changes in Kinetic Energy
• Put the three spheres in order of greatest to least kinetic
energy
• All three spheres have the same mass
B
C
A
Results
• The order of greatest to least kinetic energy is letter A has the
most, then letter C and the least is letter B
B
C
A
Law of Conservation of Energy
• The law of conservation of energy states that
energy is never created or destroyed
• Energy is converted or changed from one form
to another
Specific Heat
• Specific heat is the amount of heat needed to
raise the temperature of one gram of a
material by one degree Celsius
• The more mass an object has the more
particles of matter it contains so it can absorb
more heat energy
• The world’s oceans absorb lots of heat during
the summer and releases it during the winter
which keeps coastal climates moderate
Specific Heat continued
• The lower a material’s specific heat is, the
more its temperature will rise when a given
amount of energy is absorbed by a given mass
• For example, if equal masses of iron and
plastic absorb the same heat, the iron’s
temperature will rise more, since iron has a
lower specific heat than plastic