SHS 311 EXAM 1 QUESTIONS WITH CORRECT
ANSWERS 2026
1. What does the mass and spring represent in explaining a vibration?-ANSWER- Mass
represents inertia, spring represents elasticity
2. What is the equation for a sinusoidal vibration and what are the three para
meters in the equation?-ANSWER- D(t)=Asin(2pi*f*t + theta)
3. Cycle-ANSWER- A pattern of vibration that repeats itself
4. Period-ANSWER- Time it takes to complete one cycle (pay attention to the units)
5. Frequency-ANSWER- The reciprocal of the period, number of cycles per second
Period in s, frequency in Hz--> frequency=1/period
Period in msec, frequency in Hz-->
frequency=1000/period
6. Peak amplitude-ANSWER- The maximum vibration distance in the positive direction
7. Peak-to-peak amplitude-ANSWER- The difference between the positive and negative peaks
8. Starting Phase-ANSWER- The starting position of a vibration relative to a reference starting
point, 360 degrees
9. RMS amplitude-ANSWER- Since the simple average amplitude (d1) of a waveform is squared
(s), then the mean (m)
of these squared amplitudes is computed and the square root (r) is computed yielding the rms
(root-mean-square)
amplitude
time 0, 0.5, 1, 1,5
amplitude 0,5,0,-5
=0,25,0,25
25+25=50/4=12.5 sqrt12.5
ANSWERS 2026
1. What does the mass and spring represent in explaining a vibration?-ANSWER- Mass
represents inertia, spring represents elasticity
2. What is the equation for a sinusoidal vibration and what are the three para
meters in the equation?-ANSWER- D(t)=Asin(2pi*f*t + theta)
3. Cycle-ANSWER- A pattern of vibration that repeats itself
4. Period-ANSWER- Time it takes to complete one cycle (pay attention to the units)
5. Frequency-ANSWER- The reciprocal of the period, number of cycles per second
Period in s, frequency in Hz--> frequency=1/period
Period in msec, frequency in Hz-->
frequency=1000/period
6. Peak amplitude-ANSWER- The maximum vibration distance in the positive direction
7. Peak-to-peak amplitude-ANSWER- The difference between the positive and negative peaks
8. Starting Phase-ANSWER- The starting position of a vibration relative to a reference starting
point, 360 degrees
9. RMS amplitude-ANSWER- Since the simple average amplitude (d1) of a waveform is squared
(s), then the mean (m)
of these squared amplitudes is computed and the square root (r) is computed yielding the rms
(root-mean-square)
amplitude
time 0, 0.5, 1, 1,5
amplitude 0,5,0,-5
=0,25,0,25
25+25=50/4=12.5 sqrt12.5