1-3 Periodic Motion

What is periodic motion?

Periodic motion is simply a motion that repeats itself.

Look at the below. Could we say this wave has periodic motion?

Yes, the motion of this wave is repeating itself precisely so it is said to have periodic motion.

What affects periodic motion?

Period = (T), the time required for one complete cycle of motion

Frequency = (f), the number of complete cycles occurring in a given increment of time.

What is the relationship between period and frequency?

    f = 1/T 

    T = 1/f

Practice Problems:

1. A tennis coach paces back and forth along the sideline 10 times in 2 minutes. The frequency of her pacing is ________ Hz.

(a) 5

(b) 0.20

(c) 0.12

(d) 0.083

Answer: 1-3: 1 SEE ANSWER

2. Frieda the fly flaps its wings back and forth 121 times each second. The period of the wing flapping is ____ sec.

Answer: 1-3: 2 SEE ANSWER

3. Non-digital clocks have a second hand that rotates around in a regular and repeating fashion. The frequency of rotation of a second hand on a clock is ________ Hz.

(a) 1/60

(b) 1/12

(c) 1/2

(d) 1

(e) 60

Answer: 1-3: 3 SEE ANSWER

4. A period of 5.0 seconds corresponds to a frequency of ________ Hertz.

(a) 0.2

(b) 0.5

(c) 0.02

(d) 0.05

(e) 0.002

Answer: 1-3: 4 SEE ANSWER

5.As the frequency of a wave increases, the period of the wave ___________.

(a) decreases

(b) increases

(c) remains the same

Answer: 1-3: 5 SEE ANSWER

Continue: #REDIRECT 1-4 Simple Harmonic Motion

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