1. 38. (a) Since the brick is now horizontal and the cylinders were initially the same length , then both have
been compressed an equal amount ∆ . Thus,
∆ FA ∆ FB
= and =
AA EA AB EB
which leads to
FA AA EA (2AB ) (2EB )
= = =4.
FB AB EB AB EB
When we combine this ratio with the equation FA + FB = W , we find FA = 4 W .
5
(b) This also leads to the result FB = W/5.
(c) Computing torques about the center of mass, we find FA dA = FB dB which leads to
dA FB 1
= = .
dB FA 4