G Two cars, car 1 and car 2 are traveling in opposite directions, car 1 with a magnitude of velocity v1=13.0 m/s and car 2 v2= 7.22 m/s. If car 1’s exhaust system is loud enough to be heard by car 2 and the frequency fe produced from the exhaust is 2.10 kHz. What frequencies would be heard by car 2 when the cars are approaching, passing, and retreating from one another?

When they are approaching each other

When they are passing  each other

 When they are retreating  from each other

Explanation:

From the question we are told that

     The velocity of car one is  

      The velocity of car two is  

     The frequency of sound from car one is  

Generally the speed of sound at normal temperature is  

  Now as the cars move relative to each other doppler effect is created and this  can be represented  mathematically  as

Where is the velocity of the source of sound

            is the velocity of the observer of the sound

            is the actual frequence

               is the apparent frequency

Considering the case when they are approaching each other

Substituting value

Considering the case when they are passing  each other    

At that instant

Substituting value

Considering the case when they are retreating  from each other    

Substituting value

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.