Sunday, September 30, 2007
It seems everyone is having car problems as of late. Goodness knows why... Both of my family's cars have needed repairs and two of my friends have also had car problems. I'm starting to suspect that the repair places don't the greatest jobs either. Oh well.
On to the physical part! Going over on the H3 yesterday (I rarely go on H3 actually) I saw something that caught my eye. An old rickety brown car from what seemed to me was the 70s was really close to another car. Since we were going roughly 70 mph (112 kph) I thought, "whoa". As we started to pass the pair on left lane I realized the two were attached by a thick gnarled rope. And no, I didn't think about a picture unfortunately so the picture I do have doesn't explain the hilarious/interesting side to what I witnessed.
The rope wasn't at any angle so I figured why not calculate some work? If the car ahead was pulling the other car with a force of 15000 Newtons then over 1km 15million joules of work were needed. And I'm sure the distance was much much longer.
I'm glad that guy got someone to pull his car because a lot of work is involved. Not to mention the change in angle because of hills and the friction on the tires. And now imagine what life would be like without cars... It'd be like Virginia in 1732, rivers and poor roads (hah I'm writing a paper on Washington's formative years).
Happy rest of weekend again! Happy next week too everyone!
Sunday, September 23, 2007
Mid quarter has just passed! I'm that much closer to the end of year :) yet... I'm enjoying it all right now. For those who took Asian Studies last year, one has to enjoy the journey!
I moved my television from one floor to the other. It wasn't particularly easy work either. Sitting on its stand I first had to slide it off (with my brother's help of course, who am I, the Hulk?) and I overcame static friction to get the TV off the stand and hanging in the air. I estimate that the TV is about 70 pounds, which is roughly 32 kilograms. So thats about 314 Newtons of weight downward I was fighting with. If I had slid the TV along either the carpet or wood floor the coefficient of friction would have differed, if there was no friction then i could have pretty easily dragged the TV nearly anywhere (although stairs are different, that thing is an awkward object to move).
Well hopefully next weeks entry isnt so mundane :p oh well happy rest of weekend all!
Sunday, September 16, 2007
Hey everyone, Happy weekend! If physics were an elevator... it'd be 88 floors in reach and some little kid just pushed every button. Good thing I have my laptop though! I can thankfully still access my physics book.
So elevators. Something as mudane and as simple as an elevator still has so many physical principles. That's something I appreciate about Physics; it, more than the other sciences is right there in front of your eyes.
Now I'll never ride an elevator the same way again. So there are essentially three situations when one is in an elevator: zero acceleration (when speed is constant or the elevator car is at rest), upward acceleration, and downward acceleration. At zero acceleration the opposing forces (Fnormal and Fgravity) balance each other out and the rider (me I suppose) feels no change in my weight.
During upward acceleration however, the normal force is greater the force of gravity (which doesn't change) and one feels heavier. The opposite is true for downward acceleration when the normal force is less than gravity and one feels lighter. The same principle using the equation from Newton's second law applies to other "weightless" situations like roller coasters.
Which brings me to why there isn't a theme park here in Hawaii? Every physics student would have to go on it!
Now I got to do better on quizzes! Short term Sean goal! Physics FTW! Kikaida!