10. You are riding in a motorboat at 15 m/s away from a lighthouse. If the lighthouse emits sound from a foghorn at 250 Hz, what is the frequency of
sound you perceive? (Use v = 345 m/s for the speed of sound)

Anybody wanna ? (picture included? )

How to calculate voltage drop in a series circuit

Awelder using a tank of volume 7.50×10^-2 m^3 fills it with oxygen (with a molar mass of 32.0 g/mol ) at a gauge pressure of 3.30×10^5 pa and temperature of 37.1 ∘c. the tank has a small leak, and in time some of the oxygen leaks out. on a day when the temperature is 23.1 ∘c, the gauge pressure of the oxygen in the tank is 2.00×10^5 pa . a) find the initial mass of oxygen. b) find the mass of oxygen that has leaked out.