A device called oscillator is used to send waves along a stretched string. The string is 20 cm long, and four complete waves fit along its length when the oscillator vibrates 30 times per second. For the waves on the string:

(a) what is their wavelength?


(b) what is their frequency?


(c) what is their speed?

(a) 5cm would be their wavelength.

(b) Their frequence should be 120 Hz.


(c) Their speed should be 6m/s.


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