Stockfish - Chess Engines

Torch Engine Now Available On Chess.com's Analysis Page

Engine fighting the airplane fire

The siren of a fire engine that is driving northward at 30.0 m/s emits a sound of frequency 2000 Hz. A truck in front of this fire engine is moving northward at 20.0 m/s. (a) What is the frequency of the siren's sound that the fire engine's driver hears reflected from the back of the truck? (b) What wavelength would this driver measure for these reflected sound waves? | Numerade

animated video of a fire engine with a blazing siren on a white background