Warm-Up Exercise for lecture 15

Due 8:00 am, Tues, Oct 21

Physics 105, Fall 2008

Two people sit on a seesaw. They sit in positions such that the seesaw is balanced in a horizontal position. True/False: The two people must weigh the same amount.
true
false

In order to apply the most torque to a screw, you should:
use a wrench with a long handle
use a wrench with a short handle
there would be no difference

A meterstick is hung from a string attached to its middle, the "50 cm" mark. A rock (1 kg) is tied to the stick at the "0 cm" mark. A second rock, (2 kg)  is also tied to the stick. If the system is balanced, where must the second rock be?
at the 25 cm mark
at the 50 cm mark
at the 75 cm mark
at the 100 cm mark
none of the above

Ralph noticed that both torque and work are obtained by multiplying a force times a distance. He wants to know: how are they different? Do they have the same units? What can you tell Ralph to help him out?