A 20 kg child is the end of a long see saw, 3 m to the right of center. An 80 kg adult is 1 m to the left of center. Find the center of mass. Who will go up?
The formula for the expectation in mathematics is identical to the formula for the center of mass in physics. Mass acts like probability, and distance acts like the measured random variable. For example, suppose two people are on a see saw, and one is 2 m to the right of center and weighs 60 kg, and the other is 3 m to the right of center and weighs 50 kg. The proportion of mass in the first person is 60/110, and the proportion in the second is 50/110.
The center of mass is

In terms of balancing, these two people act like a single 110 kg person at a position 2.455 meters to the right of center.

Transcribed Image Text:

270 2455. 60 3 . 2.455. 110 11