Biomedical Engineering Reference
In-Depth Information
Exercise 3.4
Locate by the plumb line method the center of gravity of a hanger and
explain why it is in equilibrium when hanging on a bar in the wardrobe.
Example 3.2
Threading a thread through a wedding ring as shown in the figure of
Example 3.2, we see that it will be equally in equilibrium, independent of the place
where the thread passes. Explain why.
C.G.
This occurs because the wedding ring has a symmetric shape and its C.G. is exactly
at its center (does not belong to the ring). Wherever the thread passes through to hang
it, the normal force there applied and the weight, at the C.G., will be always aligned.
3.4 Analytical Method to Locate the Center of Gravity
Figure
3.6
represents a flat body which can be imagined as being composed of a
large number of small pieces, which will be designated elementary masses. The
total mass,
M
1
, will correspond to the sum of the elementary masses
m
1
,
m
2
, etc.,
1
Note that we are using the same letter
M
for the torque and total mass.
