Wednesday, November 24, 2010

iMPULSE: blog 6 :)

At the last dance team pool party, the whole team was putting their dancing skills to use when they jumped into the water. Instead of the traditional cannonball, there were countless straddles, aerials, and flips- we drove the lifeguards crazy... :)



Looking back, I realize that not only was that an afternoon of fun, but an afternoon of  physics as well. Since the water slows us down as we deccelerate to a final velocity of 0 m/s, the amount of time it takes is greater than it would be if we were jumping onto a hard surface.
Impulse= force times time
Since the water allows us to come to a stop slowly, the amount of force we feel as we hit the water is minimal. If we were to jump onto a hard surface, then the time it takes to come to rest is much smaller. Since force and time are inversely related, the amount of force we feel when we jump onto a hard surface is much greater. Good thing we dont feel very much force when we jump into water, or some of these jumps would have hurt.

Sunday, November 7, 2010

POWER: blog 5 :)

My friends and I have a special tradition where if one of us has a birthday coming up, the rest of the group plans a day of surprises for them. My friend Chelsea's birthday was during the beginning of july, and was the last of our group's sweet 16s. After secretly coordinating the day with her parents, we successfully blindfolded her and led her into the car for the start of our day of surprises :) After the hour long road trip, we finally made it to our destination- WET N WiLD :)


We spent the whole day floating in hurricane bay, sliding down the shaka, and tanning under the sun. What I didn't realize at the time, was that physics was responsible for a lot of the fun we had racing down the waterslides.
Power (Watts) = Work (Joules) over Time (Seconds)
Work is equivalent to net force times displacement, and in this scenario, the net force was equal to the force of the current of the water pushing us down the slides, minus the friction of the floaties against the water and the bottom of the slide. Displacement was equal to the length of the silde (in meters) and the time was the amount of time taken from the beginning to the end of the slide. Because the force of the current was high, the friction was low, the length of the slide was long, and the time it took to reach the bottom was short, the power of the system was HUGE. And we definately felt it on some of these rides...

Overall, it was a REALLY fun day :)