28

i just randomly looked at the sun today and i saw this crazy dude in the parachute (however you spell that). when i saw that guy slowly getting down, i realized how strong that thing must be. basically, you are going down with an acceleration of 9.8 meters per second squared. in other words, the weight force is acting on you and thats g times your mass. that means fatter people would have a greater gravity force acting on him. the air resitance is the other force vector that cancels out the weight force. the force of that is expressed in the equation which i dont really remember but you probably know it, doc, so im not gonna even write it down. anyways, so i thought, that parachute supports all kinds of people, how strong did they make it? i thought about it, and i estimated that the parachute can probably handle more than 3000N of force. because i dont think anyone would weigh more than 300kg...well, if someone did, im pretty sure he wouldnt be moving around anyways. so the maximum force that a parachute needs to handle is around 3000N, i think. well, its some random thought.

27

i was watching this japanese game show called ninja warriors today. this is a show which contestant are challenged to go through difficult obstacle courses. the reason why this is called "ninja" warriors is probably because it requires many ninja-like agility. as i was watching this show, i noticed that everything was physics-related (though we already know life is full of physics). one of the obstacle was to slide down the inclined slope and hop on to the rope and quickly turn around and jump to the net which is underneath the slide. that was like the inclined slope problem and we can pretty much calculate how fast the athlete would go. also, the rope part is representative of cons. of momentum and energy. the maximum velocity in the x firection is gained at the bottom of the rope so one must release when the rope is at the bottom. however, the energy is lost due to friction and air resistance and whatnots but we can estimate and analyze this whole motion...if we wanted to.

26

today i noticed/realized something interesting. i probably would have never thought about this if i didnt take ap physics with you, doc. while i was walking around today, i was pushed by a really strong wind. it was so strong i had to pretty much had to lean over and gave a little more strength in each step i take. then i realized, wait a second, how does this happen and how would i calculate this bad boy. i understand air resistance because it is like friction, its just there and you know it since there must be somekind of force to against the force put in. wind, on the other hand, is an interesting force. its just there 24/7 like jack-in-the-box drive thru but depending on the days and time, the strength differs. i just wondered, how the heck does this occur. is it because earth is rotating? how would be calculate how much force a wind exerts on us? it may be quite interesting to figure those stuff out.

25

again, i will talk about track, doc. there was one thing which i noticed during a track meet. while i was watching one race, i reconfirmed myself that the speed of light is faster than the speed of sound. i was on the other side of the track when the official made a gun shot into the sky. i saw smoke coming out of his gun but i heard no sound until maybe like .3-.5 second later. it was pretty cool, i must say because when i was near the official, the smoke coming out and the sound go off at pretty much the same time. this is probably the reason why the hand time and electronic time for state qualifying time is different. because the timer is some distance away from the starting line, they would have a lag when they start their clock. it probably involves human reaction time and whatnots but whatevers. whereas, when it is done electronically, then there would be almost no lag since there is no human error involved (yay to the technologies).