Ch 5: Mechanics II

Question 1

For center of mass problems, what formula do you need to use?

Answer 1

This is the “weighted average” formula:

x_cm = m₁x₁ + m₂x₂ + m₃x₃ …./ (m₁ + m₂ + m₃…)

Remember to choose a reference point to call x = 0. If you choose that point to be the center of the stick, remember to use negative values for those masses that are hanging on the left half of the meter stick.

Question 2

What is fascinating about the location of the center of mass of nonhomogeneous or irregularly shaped objects?

Answer 2

The center of mass may not even be located within the body of the object.

(Recall the example of a high jumper arching their back to get over the pole.)

p. 105