B. Find the average frequency of a police car siren if at rest is has a frequency of 1800 Hz but has a frequency of 2000 Hz as it moves towards you.​

Answer: it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.explanation:   we have equation of motion ,where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.average velocity = displacement/ time taken.average velocity = 10.69 miles/hr = 10.69*1.6*1000/(60*60) = 4.75 m/s4.75 = s/ts = 4. 1we also have acceleration = 2.18 m/s², initial velocity = 0 m/sso it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.

The independent variable in this experiment is the angle at which the light from the ray box strikes the mirror.hope this .

It would be c hope this out

The answer is: c. from underground