Physics Blog 9

Last Sunday night, I was watching the new episode of Family Guy on Fox.  After it was finished, I went to do physics homework worksheet 24A, I remembered the episode of Family Guy where Peter becomes electric man.  In the beginning of the episode, he gets a fury body suit and throughout the episode he terrorizes his family by shocking them.  I then went back and watched that segment of the episode and related it to physics.  Peter rubs his feet on the rug to become positively charged due to friction.  He then touches one of his family members to reduce the charge imbalance.  Peter then becomes neutral again.  Although this episode was hilarious, it was inaccurate.  The rug and the suit were probably made from similar materials and therefore they have the same desire for their electrons.  Peter would not have become positively charged because he would not lose electrons through friction.  What a killjoy.

 Heres a clip (Terrible Quality):

Physics Blog 8

Last night, before I went to sleep, I turned on the light switch to see (obviously).  But because, the light in my room has an integrated fan, when I turned on the light switch, both the fan and the light came on.  Because it was really cold, I turned on my lamp and then proceeded to turn off the light switch.  As I walked over to the wall, I realized that the fan had a moment of inertia which is what we just studied in physics.  Moment of inertia, I, is generally equal to mr^2.  However, for the fan, I is different.  The fan has five blades and each blade has an I of 1/3mL^2.  This means in the system, the moment of inertia is the sum of those blades so I=5 (1/3mL^2).  One blade has a length of around 1 meter and the mass is approximately 2.2046 kg.  Therefore, I= 3.67433333 kg*m^2.  On the lowest setting, the ceiling fan takes around 25 seconds to get to its top speed of 5.66052731 rad/s. From this information we can find net torque because rotational acceleration= net torque/ I.  Alpha = change in rotational velocity/ time.  5.66052731/25= 0.226421092 rad/s ^2.  Net torque = I* Alpha so Net torque = 0.831946565Nm.