2. Friday, March 19th Agenda Collect Conservation of Energy Worksheets
Lab Discussion
Lab: “Determining Energy for a Rolling Ball”
Homework: NONE!

3. Lab: “Determining Energy for a Rolling Ball”
In this lab, you will be calculating a ball’s kinetic energy as it rolls down a ramp and comparing that value to the potential energy that the ball has at the top of the ramp.

4. Lab: “Determining Energy for a Rolling Ball”
Take a few minutes to read through the lab to become familiar with the procedure…

5. Lab: “Determining Energy for a Rolling Ball”
The first step in conducting this lab it to make a data table to record your data.
You will be making a ramp out of a piece of wood and a stack of books.
You release a ball from the top and time the amount of time it takes to reach the bottom of the ramp.

6. Lab: “Determining Energy for a Rolling Ball”
Using the equations for kinetic and potential energy, you will calculate both the kinetic and potential energy of the ball and compare the two.
You will test 3 different ramp heights and compare the energies you find.
Once everyone is finished collecting data, we will come back into the classroom for the calculations.

7. Lab: “Determining Energy for a Rolling Ball”
There are no real safety issues with this lab, but still be careful…
Have fun!

8. Lab Calculations To convert grams to kilograms:
Divide your number of grams by 1,000
To find the average time ball traveled (s):
Time ball traveled for trial #1
Time ball traveled for trial #2
+ Time ball traveled for trial #3
Answer
b. Divide Answer by 3 to get average time (s)

9. Lab Calculations To calculate the average speed of the ball (m/s):
Average speed = length of ramp (m)
average time ball traveled (s)
To calculate final speed (m/s):
a. Multiply average speed by 2 to get final speed

10. Lab Calculations To calculate final kinetic energy (J):
a. Use the equation for kinetic energy
KE = ½ X (mass of ball) X (final speed)2
To calculate initial potential energy (J):
a. Use the equation for potential energy
PE = (mass of ball) X (9.8 m/s2) X (ht of ramp)

11. Defending Your Conclusions
On a separate piece of paper, answer these questions on COMPLETE SENTENCES using information from your data table.
Be sure to answer ALL PARTS of the questions, not just a Yes or No…