Apolice car parked on the side of the highway emits a 1200 hz sound that bounces off a vehicle farther down the highway and returns with a frequency of 1250 hz. how fast is the vehicle going? a. 8.9 b. 6.9 c. 6.5 d. 5.6

f' = frequency observed by the police car after sound reflected from the vehicle and comes back to police car = 1250 Hz

f = frequency emitted by the police car  = 1200 Hz

V = speed of sound = 340 m/s

v = speed of vehicle = ?

frequency observed by the police car is given as

f' = f (V + v)/(V - v)

inserting the values in the above equation

1250 = 1200 (340 + v)/(340 - v)

v = 6.9 m/s

1. B) 2120 Hz

2. A) 7.7 m/s

3. B) 6.9 m/s

4. C) 0.80 m; 431 Hz

5. A) 2186 Hz

6. A) the frequency of the siren is higher and the wavelength is shorter than it was at first

7. C) 300 x 10^7 m/s

8. A) 1500 Hz

9. D) 2000 Hz

10. D) 780 m/s

Explanation: 100% physics lesson 2 :)

answer: d. a cme increases the amount of energy in the solar wind

explanation:

coronal mass ejections, also called cmes, are large clouds of plasma and magnetic field that erupt from the sun. only when the cloud is aimed at earth will the cme hit earth and therefore cause impacts. high-speed solar wind streams come from areas on the sun known as coronal holes.