Aperson produces a sound to a reflector 15 metre away from him and starts running at the opposite direction of reflector with a velocity of 20 m/s. velocity of sound of that day was 347.65 m/s .can he hear the echo of the sound

Calculate the work done by an external agent during an isothermal compression of 1.00 mol of oxygen from a volume of 22.4 l at 10∘c and 1.0 atm pressure to 16.8l

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

The difference between a red shift and a blue shift has to do with wavelength frequency. t or f