Name _____________________________ Section (Period) _________________ Date __________________
Lab Partner(s) _____________________________________________________________________________
P A P E R R O L L E R C O A S T E R L A B
Calculating Potential Energy and Kinetic Energy of
a Rolling Marble
INTRODUCTION AND OBJECTIVES
The Law of Conservation of Energy states that energy can be
neither created nor destroyed. However, energy can change from
one form to another. In the case of a marble on a paper roller
coaster, a marble starts at the top of the roller coaster with a
relatively large amount of potential energy and no kinetic energy.
As the marble starts rolling down the roller coaster, the amount of
potential energy stored in the marble decreases while its kinetic
energy increases. Potential energy is also converted into heat
energy due to friction. In this experiment, you will be calculating
the change in potential energy of a marble traveling between two
points on a paper roller coaster and compare that to the kinetic
energy that was gained by the marble during that same time.
EQUIPMENT NEEDED
completed Paper Roller Coaster
ruler
pencil
calculator
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stopwatch (optional)
video camera (optional)
photogate timer (optional)
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PROCEDURE
I. Selecting the starting and ending points.
Choose a portion of the roller coaster in which the
marble accelerates and then keeps a fairly constant
speed. Ideally, this would mean a gentle downhill sec-
tion followed by a level section. The marble does not
need a steep hill to accelerate.
Place three marks on the roller coaster. Label the be-
ginning of the hill “A”, the end of the hill “B”, and the
end of the level section “C”. You will be measuring
the distance between each of these points so make sure
that those distances will be easy to measure.
II. The gravitational potential energy of the marble
To simplify calculations, treat the height of point
B as the reference point where gravitational poten-
tial energy equals zero. The gravitational potential
energy of the marble depends on the height of the
Find the mass of the marble. Measure the mass of ten marbles and divide that by ten. Convert the mass of the
marble to kilograms. Enter your result below.
Find point A’s height above point B in meters.
1. Mass of the marble, m (kg)
2. Acceleration due to gravity, g (m/s
2
)
3. Height of point A above point B, h (m)
4. Gravitational potential energy at point A, mgh, (J)
starting point compared to the ending point of the
marble’s path. Gravitational potential energy equals
(mass)*(acceleration due to gravity)*(height). This
can be written as P.E.= mgh.
©2012 Paper Roller Coaster Company
A
A
B
C
h