Energy of a Rolling Ball Name
____________________________________
Raised
objects have gravitational potential energy. Moving objects have kinetic
energy. How are these two quantities related in a system that involves a ball
rolling down a ramp?
Purpose:
To find a ball’s potential energy at the top of a ramp and its
kinetic energy at the bottom of a ramp and to look at the relationship between
the two.
Equipment
Board Meter stick Golf
Ball Books
Stopwatch Masking Tape Balance
Procedure
 Measure
the mass of the golf ball and record it in the data table.
 Place
a strip of masking tape across the board close to one end and measure the
distance from the tape to the other end of the board. Record this distance
as the length of the ramp
 Make a
stack of books approximately 10 cm high. Build a ramp by setting the taped
end of the boardon top of the books. Measure the
vertical height of the board at the tape and record this as the height of
the ramp.
 Place
the ball on the ramp on the tape. Release the ball and measure how long it
takes the ball to travel to the end of the board. Record the time in your
data table.
 Repeat
step 4 two more times and record the results in your data table. After
three trials calculate the average time and record it in your data table.
 Repeat
steps 3 5 with the books approximately 20 and 40 cm high.
Data Table

Height 1

Height 2

Height 3

Mass of ball(g)




Length of ramp (cm)




Height of ramp (cm)




Time of travel, trial 1




Time of travel, trial 2




Time of travel, trial 3




Average Time of travel




Calculations: Show your work and include the units
 We
measured the length of the ramp in centimeters. Find the length of the
ramp in meters. There are 100 cm in one meter.
 Calculate
the average speed of the ball in each using the following equation
_{}
 Multiply the final the average speed by 2 to find the
final speed.
 We measured the mass of the ball in grams. Find the
mass of the ball in kilograms. There are 1000 g in one kilogram.
 Calculate the kinetic energy of the ball for each
trial using this equation
_{}
 We measured the height of the ramp in centimeters.
Find the height of the ramp in meters for each trial. There are 100 cm in
one meter.
 Calculate the potential energy for each trial using
the following equation
_{}
 For each of the three heights compare the ball’s
potential energy to its kinetic energy.
 Why should the value for kinetic energy be less than
the value for potential energy.