1. PHYS16 – Lecture 17 Ch. 8 Energy Conservation "It checks out OK on the computer, now let's confirm it with the pendulum."

2. Energy Pre-question Two balls have the same mass. Ball 1 is thrown upward at 3 m/s and Ball 2 is thrown downward with 3 m/s. Which Ball reaches the ground with more kinetic energy? A)Ball 1 B)Ball 2 C)Both balls have the same kinetic energy D)There is not enough information

3. Conservative vs. Non-conservative Forces Conservation of Energy – Basic Equations – Systems without Friction – Systems with Friction Power Ch. 8 Energy Conservation

4. P16 at the Circus…

5. The Trapeze Artist A trapeze artist launches from a platform with a 40-m-long rope at a 20 degree angle from the vertical. What is the speed of the artist at the bottom? How high will she go on the other side if there is no air resistance?

6. Human Canonball? A cannon ball hangs from a wire. If I hold the cannon ball to my face and let go, will I get hit when the cannon ball swings back? What two things should I not do…

7. Human Cannonball We want to shoot out Evil Knevil (mass = 68.4 kg and length =1.75 m) and have him grab a bar 7.5 m above the cannon. Cannon is 4 m long and equil. position of spring is at the top of the cannon. Knevil depresses the spring 3.3 m. What is the spring constant needed?

8. Human Cannonball What is the speed he reaches at the end of cannon?

9. Monkeys down the slide… A monkey (23 kg) slides down a 35 degree slide that is 25 m long. When the monkey reaches the bottom he keeps going on a horizontal part. Coefficient of kinetic friction is 0.1. How far does the monkey go? http://lh3.ggpht.com/_z8sPAlwCN_8/R0wfRchlfVI/AAAAAAAAAcg/gUwvXfLuUxg/CIMG3060.JPG

10. Conclusions Conservative vs. Nonconservative Forces Energy Conservation