Question

Two motors in a factory are running at slightly different rates. One runs at 825.0 rpm and the other at 786.0 rpm. You hear the sound intensity increase and then decrease periodically due to wave interference. How long does it take between successive instances of the sound intensity increasing

Answer 1

Answer:

$T=1.54s$

Explanation:

From the question we are told that:

Speed of Motor 1 $\omega_1=825rpm=>2 \pi 13.75$

Speed of Motor 2 $\omega_1=786rpm=>2 \pi 13.1$

Therefore

Frequency of Motor 1 $f_1=13.75$

Frequency of Motor 2  $f_2= 13.1$

Generally the equation for Time Elapsed is mathematically given by

$T=\frac{1}{df}$

Where

$df=f_1-f_2$

$df=13.75-13.1$

$df=0.65Hz$

Therefore

$T=\frac{1}{65}$

$T=1.54s$