Select the appropriate sensor(s), measure(s) and frequency range
to obtain valid vibration data for a single-reduction gearbox
driven by a small turbine with rolling element bearings. The
turbine operates at 2846 RPM, the output shaft rotates at 987 RPM,
the ball pass frequency of the inner race is 8290 CPM, and the gear
mesh frequency is 122,378 CPM. Justify your choices.
A car and the suspension system are a damped spring, mass
system, with a natural frequency 2 Hz and a damping coefficient
0.2. The car drives at speed V over a road with sinusoidal
roughness. The roughness wavelength is 20 m, with a amplitude of 50
cm. What speed does the maximum amplitude of vibration occur? What
is the corresponding vibration amplitude?
Please do not use an older solution.
A spring mass system with a natural frequency fn = 12 Hz is
attached to a vibration table. The table is set to vibrate at 16
Hz, 0.5 g maximum acceleration:
a. What is the amplitude of the table's motion in inches?
b. What is the magnification factor M of this undamped
system?
c. What is the maximum displacement of the mass assuming no
dampening?
d. What is the maximum acceleration of the mass assuming the
packaging can be modeled...
How many electrons does a neutral potassium atom have? How
many protons? How many electrons does a neutral fluorine atom have?
What happens in the molecule of potassium fluoride?
How many electrons in an atom could have these sets of quantum numbers?
n=2 --> number electrons = ?
n=5, l=2 --> number electrons= ?
n=7, l=1, ml=-1 --> number electrons= ?