You are driving along a highway at 35.0 m/s when you hear the siren of a police car approaching you from behind and you perceive the frequency as 1310 hz. you are relieved that he is in pursuit of a different speed when he continues past you, but now you perceive the frequency as 1240 hz. what is the frequency of the sirenin the police car

1270.44 Hz

Explanation:

 = velocity of the our car = 35.0 m/s

 = velocity of the police car = ?

 = velocity of the sound = 343 m/s

 = frequency observed as police car approach = 1310 Hz

 = frequency observed as police car go away = 1240 Hz

 = actual frequency of police siren

Frequency observed as police car approach is given as

inserting the values

                         eq-1

Frequency observed as police car goes away is given as

inserting the values

                         eq-2

Dividing eq-1 by eq-2

 = 44.3 m/s

Using eq-1

f = 1270.44 Hz

i guess it’s a and b

current and voltage can both be different in different parts of a circuit so it matters where you place the ammeter and voltmete