Good+Bad+and+Ugly+physics

__Good:__ Project A with Jackie Chan. Falling from a three story building through 2 awnings. Kinematics As Jakie Chan falls from a three story building gravity causes him to fall with an acceleration of 9.8 m/s. If Jackie weighs about 70 kg then the force he is falling downward or his weight (F = mg) is 686 N. If the average height of a three story building is 30 ft(9 meters) an Jackie had fallen without hitting the awnings he would have hit the ground at 13.3 m/s. Jackie's velocity after hitting the first awning is 7.67 m/s and after the 2nd awning its a little more than half of that m/s. When he finally hits the ground his velocity is around 2 m/s which is considerably less than 13.3 m/s and is a much safer fall. the velocity decreased because when Jackie hit the awnings they acted back up on him and slowed his fall. Watch from 3-3:45 min [|jackie falling clip]

__Bad:__ Honey I Shrunk the Kids. 4 kids are shrunk to a size smaller than an aunt. The length of their vocal chords decreased as their body sized decreased but the frequency of their voices stayed the same. The frequency of their voices should increase significantly, since the wavelength of the voice will probably decrease proportionally with the body length. this is all inferred with the equation wavelength = frequency x velocity. So, assuming initial height 180cm, final height 1cm, as well as a bass note at 80Hz. The "same" note as sung by the miniature guy will have a frequency around 14kHz. I.e. almost inaudible. Not to talk about the amplitude, which would be much smaller. Their ears would be affected similarly. They wouldn't be able to hear the bass notes that we can hear. If our lower threshold is 20Hz, theirs would be 3600Hz, which is already quite trebly (almost the highest note on the grand piano). Watch clip from 1:30-3 min [|honey i shrunk the kids clip]

__Ugly:__ Speed with Keanu Reeves. A bus jumps a 50ft gap in the road. Projectile Motion In the movie Speed a bus going 70mph (or 31.29 m/s) jumps a 50 ft (or 15.24 meter) gap. We will assume that there is no angle in the ramp and that the ramps are even in height with each other. If you try to find the time by assuming that the bus does jump the 50 ft you can find the time it would take for it to do so using the equation d = v/t. Rearrange for t and get t = v/d = 31.29 / 15.24 = 0.487 s. Because time is equal in both the x and y directions we can then use the time we found that it would take to jump the 50ft gap and use it to see if the bus would fall any distance. We can use the equation d = vit + 1/2 a t squared. The a of course being acceleration due to gravity. Because vi is 0 the equation becomes d = 1/2 a t squared. = 1/2 (9.8) (.487)squared = 1.16 meters. The bus would not have made the jump because it would have fallen 1.16 meters and ran into the ramp instead of landing on it. [|bus jump clip]