Pipe A is open at both ends and long

PHYSICS · Subjective · A Level · Physics · Waves · Waves

Problem

Pipe A is open at both ends and

30\,\text{cm}

long. Pipe B is also open at both ends and

40\,\text{cm}

long. If pipe A vibrates in its third harmonic while pipe B vibrates in its fourth harmonic, find the ratio of their frequencies

f_A : f_B