A police car siren emits a frequency of 2010 Hz when stationary. Another car
hears a 1920 Hz sound when it drives
away from the stationary police car.
How fast is the second car driving?
(Speed of sound = 343 m/s)
(Unit = m/s)

Aboxcar traveling at 12 m/s approaches a string of 5 identical boxcars sitting stationary on the track. the moving boxcar collides and links with the stationary cars and they all move off together along the track. what is the final speed of the cars immediately after the collision? (you may take the mass of each boxcar to be 18,537 kg.)

The boy of mass 30 kg is at r1= 2 meters from the fulcrum. of the girl is 45 kg, at what r2 must she sit so that they are balanced ?

The speed of light can be used to measure the