A 1000kg car carrying two 100 kg football players travels over a bumpy road with the bumps spaced 3 m apart. The driver finds that the car bounces up and down with maximum amplitude when he drives at a speed of 5 m/s. The car then stops and picks up three more 100 kg passengers. By how much does the car body sag on its suspension when these three aditional passengers get in?
A 200g uniform rod is pivoted at one end. The other end is attached to a horizontal spring. The spring is neither stretched nor compressed when the rod hangs straight down. What is the rod's oscillation period? You can assume that the rod's angle from the vertical is always small.
The Attempt at a Solution
#1 I have stared at this problem for awhile, trying to figure out what "maximum amplitude should tell me. vmax= omega* A But that doesn't really lead me anywhere.
Hmmm... w= sqrt k/m and I don't know the k. Any hints would be greatly appreciated.
#2 If the rod weren't attached to the spring
I=(1/3)*(.200kg)(.20m)^2 I= .0027 kgm^2
so omega= sqrt [(.200kg*9.80*.10m)/.0027kgm^2] and from there I could find the period. However, I cannot visualize how the spring would affect this physical pendulum other than decreasing its amplitude possibly.