Ch+2+Sec+9+KirnumB

=Section 9=

Watching someone's hang time
 * What do you see?**

The hang time of some athleets doesnt defy the pull of gravity, they have longer hang times because they know how to use the force of gravity and how to make their hang times longer.
 * What do you think?**

A world-class figure skater doesn't defy gravity to remain in the air to do a triple axel, they spin which helps keep them in the air/


 * Physics Talk**


 * Elastic potential energy in a spring is due to compression of the material making up the spring
 * Objects can gain energy
 * ex: the collision between a player's foot and a soccer ball
 * the ball gains kinetic energy and moves faster


 * Checking up**
 * 1) The energy that allows the jumper to move from the ready position to the launch position comes from the EPE of his mussles.
 * 2) In the launch position you have PE and EPE. Durring the peak of the jump they will have KE and GPE
 * 3) Three other types of Energy
 * 4) Gravitational
 * 5) Elastic
 * 6) Static

4. 20 frames, 2/3 of a second 5. 31 frames, 1 and 1/3 of a scond
 * Investigate**

1. W fd GPE mgh 2. a. We will be able to calculate the force needed to jump a hight. b. We will record distance, height, and mass. c. We will use the scale from data studio, and a meter stick. d. We will analyze our data by putting it in an equation and sloving for F then using the scale to find out how close our measurements were

5. My calculation was _, the scale said it was 1104 they were very close


 * PTG**

> > > b 563 J > b 2.7
 * 1) [[image:Screen_shot_2011-01-11_at_7.40.16_AM.png]]
 * 2) You can record movement by using data studio
 * 3) The person who is claiming should be the one to look into it.
 * 4) ^F increase muscle strength
 * 1) same as 6
 * 2) same as 6
 * 3) [[image:Screen_shot_2011-01-11_at_7.43.02_AM.png]]
 * 4) 2084J
 * 5) a 6m/s^2
 * 1) a 12.5
 * 1) [[image:Screen_shot_2011-01-11_at_7.44.06_AM.png]]
 * 2) [[image:Screen_shot_2011-01-11_at_7.46.05_AM.png]]

16.
 * || GPE || EPE || KE || SUM ||
 * running || 0 || 0 || 200 || 200J ||
 * bend || 80 || 120 || 0 || 200J ||
 * peak hight || 190 ||  || 10 || 200J ||
 * landing || 0 || 0 || 200 || 200J ||
 * collapsing on cushion || 0 || 0 || 0 || 0 ||
 * || GPE || EPE || KE || Sum ||
 * peak height || 250 ||  || 50 || 300J ||
 * landing || 30 || 220 || 30 || 300J ||
 * lowest point || 0 || 300 || 0 || 300J ||

17.
 * || GPE || EPE || KE || Sum ||
 * top || 250 || 0 || 0 || 250J ||
 * middle || 125 || 0 || 125 || 250J ||
 * bottom || 0 || 0 || 250 || 250J ||


 * What Do you think now?**

There is no such thing as a hang time so athletes do not defy gravity. Figure skaters dont defy gravity to remain in the air long enough to do a triple axel because they do not stay in the air and defy gravity.__