Download Marble Energy conservation Lab (light)

Marble Energy conservation Lab (light)
Theory:
In an ideal system, the transfer of gravitational potential energy into
kinetic energy will be 100%. Therefore, if the potential energy of a system is known,
it is possible to calculate the kinetic energy and therefore the final speed of the object.
Using a ramp, a ball bearing will be raised to a certain height and allowed to roll
down the ramp. At the bottom of the ramp the velocity should be such that the
potential energy at the top of the ramp is equal to the kinetic energy at the bottom. In
order to calculate the velocity at the bottom of the ramp, the bearing will be allowed
to roll off the table top and fall to the floor. An object that leaves a surface with only
horizontal velocity will begin to fall with the acceleration due to gravity and take the
same amount of time to reach the floor as if it were dropped. Therefore, if the height
of the table is known, it is possible to calculate the time it falls and using horizontal
distance, the initial velocity.
Materials:
Triple beam balance
Ball bearing/Golf ball/Marble
Metre stick(s)
Ramp
Procedure:
1)
2)
Setup a ramp that will allow a ball to roll onto the table top and then
off the table and onto the floor.
Measure the following:
a) Height of the table (H=_________)
b) Height of the ramp (4 release points)
c) Mass of the ball bearing (M = _________)
3) Release the ball bearing on the ramp and record where it hits the
ground. Measure the horizontal distance from the table edge to
where the ball hit the floor. Repeat this until you have five trials.
Height 1
Height 2
Height 3
Height 3
Trial 1
Trial 2
Trial 3
4) Using the other release points, repeat step 3.
Data Analysis
1. Calculate the potential energy of the system at each of the release points.
2. Using kinematics, calculate the time the ball should have taken to fall from the
height of the table to the floor.
3. Calculate the average horizontal speed for each of the systems.
4. Calculate the average kinetic energy for each of the systems and compare this
value to the potential energies.
Summary Questions
1. Assuming that all energy losses were due to friction, what percentage of the
potential energy was converted into kinetic energy in each case?
2. Did you need to record the mass of the ball bearing in order to complete these
comparisons?