David M. Beams
Homework Assignments
Updated Aug. 2, 2005
Numbers
with decimal points (e.g., 2.9) refer to problems from the course text. Numbers in parentheses give the point value
for the problem.
In-class
assignment (10)
An
aluminum beam has a length of 11.5 in, a width of 1.0 in, and a thickness of
0.0625 in. It is clamped at one end and
left free at the other to form an end-supported (cantilever) beam. A 120W metal-foil strain gage is bonded to the beam at 1.5 in from
the clamped end of the cantilever. The
strain gage has a gage factor of 2.095 and the aluminum has a modulus of
elasticity (Young’s modulus) of 68.9 GPa.
What will be the change in resistance in the strain gage if a mass of
250g is suspended from the free end of the cantilever?
Other
assignments: transfer function of an
active single-pole phase shifter, determination of the potential of a sphere
the size of the Earth carrying a net charge of 1 C (5 points each)
You
will need the slew rate for the CA3140 for 5.3.
You can find it from the data sheet available at
http://www.intersil.com/data/fn/fn957.pdf.