Energy & the Roller Coaster
Question: How is motion on a roller
coaster related to energy?
need
 directions
At which place do you think the
marble moves fastest?
 Why?
At which place do you think the
marble moves fastest?
 Fastest 6,3,2,4,5,1 Slowest
 As height decreases, speed increases.
 As height increases, speed decreases.
 The fastest speed is at the lowest part of the roller
coaster.
Kinetic & Potential Energy
 Kinetic energy is the energy an object has when it
is in motion. This kind of energy depends on speed.
 Potential energy is stored energy. This energy
depends on how high an object is relative to a
surface.
The Flow of energy between
potential & Kinetic along the roller
coaster.
 Before the marble starts, it has mostly
potential energy and no kinetic energy.
 The marble’s potential energy becomes
kinetic energy as it rolls downhill.
The Flow of energy between
potential & Kinetic along the roller
coaster.
 At the bottom (3), the marble has almost all
kinetic energy an not much potential energy.
 The marble’s kinetic energy becomes potential
energy again when it rolls uphill.
The Flow of energy between
Potential & Kinetic along the roller
coaster.
 At the top of the hill, the marble once again has mostly
potential energy and not much kinetic energy.
 Then, the marble rolls back downhill, and once again its
potential energy becomes kinetic energy.
 The marble has the most potential energy at the start
of the track.
The Flow of energy between
potential & Kinetic along the roller
coaster.
 The marble is going very fast at the bottom
of the hill.
 This is the point where the marble has the
greatest amount of kinetic energy and the
least amount of potential energy.
Energy conservation
 When the marble speeds up, it gains kinetic energy
from falling down a hill. Kinetic energy is energy of
motion.
 The kinetic energy is converted from the potential
energy (the stored energy) the marble had at the
top of the hill.
Energy conservation
 As the marble travels, it trades potential
and kinetic energy back and forth.
 This conversion of energy from one form to
another is explained by the law of
conservation of energy.
The law of conservation of energy
 Energy can be converted from one form to
another but not created or lost.
The law of conservation of energy.
 As one form of energy decreases (potential
energy is related to height) the other form
of energy increases (kinetic energy is
related to speed).
The law of conservation of energy.
 There’s a balance in the energy
transformation, not that energy is
increasing.
 This is the law of conservation of energy.
Questions

If the roller coaster was shaped like the drawing, list the
numbered positions in order from where the marble has the
fastest speed to where the marble has the slowest speed.