1. Pendulum Practicum
Physics

2. Before the Lab Data Collection: Height of Ramp: Distance to Floor:
(What you will measure.) h d h d
Have a student measure the height of the ramp and the distance from the counter to the floor. Everyone will write it down.
Height of the Ramp: .44 m ish
Distance to Floor: .94 m ish
Before the Lab
Just use the ramp height for Part 1
Just use the distance for Part 2

3. Part 1 = Energy mghtop mgh1/2 + ½ mv2 ½ mv2
First we will solve for the launch speed by using the conservation of energy.
Draw an energy pie chart for the marble at the top of the ramp, middle of the ramp, and bottom of the ramp. DON’T INCLUDE HEAT!!!
mghtop
mgh1/2 + ½ mv2
½ mv2
Part 1 = Energy

4. What is the height the marble fell from the top of the ramp to the bottom of the ramp?
How much gravity energy did we have up on top? (Just leave the unknown mass as ‘m’.)
What kind of energy do we have at the bottom?
e. Conservation says that part c and part d should be equal. Use this to solve for the launch velocity.
height we measured
mgh
Kinetic ½ mv2
mgh = ½ mv2
Solve for v
Part 1 = Energy

5. Part 2 = Two Dimensional Kinematics
Use kinematics in the y-dimension to solve for the drop time of the marble.
Y-DIM Equation: Solve for t.
x =
v o =
v = Drop time =
a =
t =
x = ½ at2 + vot
t = √2∆x/a
d (distance to floor)
0 m/s
Impact velocity (DC)
9.8 m/s2
want
About .2 s is a good number for the time. Have them plug in numbers and check their answers with the class.
Part 2 = Two Dimensional Kinematics

6. Part 2 = Two Dimensional Kinematics
Use common sense in the x-dimension to solve for how far the marble will move forward in this time. Remember that the horizontal speed of the marble equals the speed we calculated in part one using energy.
Y-DIM Equation: Solve for x. .
x =
v = c=
t =
v = x/t
∆x = v∆t
landing length (want)
Velocity from Part 1
time from part 2.a.
x is where you place the target. In my classroom it should be about 1.28 m-ish.
Part 2 = Two Dimensional Kinematics

7. Pendulum Practicum Lab
DON’T FORGET ABOUT AIR RESISTANCE!
PLACE THE BACK OF THE TARGET AT THE PREDICTION POINT!