PHYSICS BLOG 2

Sunday afternoon, I was bored of doing history homework so I decided to take a break and play some MarioKart. I was trying to break a time trial at coconut mall and flying off a ramp reminded me of projectile motion. I wondered if I could complete the course faster if I just drove around the ramp instead of trying to use it to propel me foward faster. First i would have to time how long before the car hits the ground. Then if the cars initial velocity and the angle of the ramp was known, I could easily calculate the x and y components of the vector using the formulas vcos(angle)=Vx and vsin(angle)=Vy and figure out the distance the car travels accelerating up and down at -9.8m/s with constant horizonal velocity. Finally compare the results with the time it takes to travel the same distance with out a ramp using time=distance/velocity. I learned its faster to go straight avoiding the ramp than travel unecesary distance vertically.

Free Fall

A couple days before school started, my friend took me on a hike two ridges over from Aiea. We left early morning so it wouldn't be too hot. To get to the hike you had to walk up a road past a gate. The beginning of the trail was dirt and flat until a point where you had to go downhill through the forest. It had rained the night before so the rocks were muddy and slippery resulting in me eating it at least once d: It was all worth it though. Along the trail were beautiful views, and at the the end we discovered a waterfall which we had to ourselves for about half an hour since we left early.

There were two pools to swim in. The one the waterfall initially flowed into was pretty big and shallow, but at the end the water dropped off a cliff into another smaller pool. You could either swing on a rope into the smaller pool, which i did, or you can jump off the cliff.

Physics is present in both scenarios.

I chose the video of Brian doing a backflip off because it showed free fall which we recently learned about. The force he used to jump gave him an initial velocity in a positve upward direction until gravity slowed him down hitting his peak at velocity of zero. Now he began to accelerate at -9.8m/s2 in a negative direction with increasing speed until he hit the water. If you time how long it takes him to hit the water after he hits his peak it would be possible to calculate his final velocity before hitting the water. Enjoy! :)