A progressive wave of frequency and wavelength travels along a rope

PHYSICS · Single correct · A Level · Physics · Waves · Waves

Problem

A progressive wave of frequency

20\,\text{Hz}

and wavelength

0.50\,\text{m}

travels along a rope. Two observations of the displacement at positions

A

and

B

are made

4.0\,\text{ms}

apart in time. What is the minimum distance between

A

and

B

so that the two observations are in phase? (a)

0.25\,\text{m}

(b)

0.04\,\text{m}

(c)

0.50\,\text{m}

(d)

0.08\,\text{m}