2. Lets get ready to Bungeeeeeeeeeee! We will quickly review Hooke’s law and energy to prepare for our bungee jumper simulation experiment on Tuesday.

3. Types of Energy In Bungee we have. Kinetic energy Gravitational potential Elastic potential

4. Let’s get ready to BUNGEEEEEEEEE! A bungee jumper starts with gravitational potential energy. It is converted into Kinetic and elastic potential. And finally into entirely elastic potential

5. Let’s get ready to BUNGEEEEEEEEE! For our problem, the middle state is not important. Simply, all the original potential must be stored in the bungee at the bottom.

6. Finding Elastic potential Using U=1/2kx 2 is trickier First we must find k for our Bungee. X is the length stretched from its original. This takes some thought and a subtraction.

7. Hooke’s law Using F= -kx k = -F/x, so you need to find at least one and I recommend a few data points. F is the force applied X is the length the spring stretches. If you have several data points, you can get an average. BELDEN is the best

8. Let’s try a deomonstration in class together Constructing your bungee. Measure unstretched length Put a load on the bungee. Measure new length Calculate K

9. A practice problem A 75-kg man who is 1.5m tall wants to bungee off a building that is 45m tall. How long should the bungee (k=500n/m) be (when measured lying on the ground before his jump)? Find x using chart Find length you want to fall (include some factor of safety) Calculate original length of Bungee.

10. Now, use what you learn I hope your bungee jumper does not die a horrible death. You won’t get me up on your bridge any time soon.