If i jump of a 20 story building and dropped a iphone playing music, would i hit the floor first or the phone? and would i hear the music with falling?

Determine the age of a fossil if it had only one eighth of its original carbon-14 content remaining?

Wavelength of 125 meters is moving at a speed of 10 m/s. what is it's frequency?

Two kilograms of air within a piston–cylinder assembly executes a carnot power cycle with maximum and minimum temperatures of 800 k and 300 k, respectively. the heat transfer to the air during the isothermal expansion is 60 kj. at the end of the isothermal expansion the volume is 0.4 m3. assume the ideal gas model for the air. determine the thermal efficiency, the volume at the beginning of the isothermal expansion, in m3, and the work during the adiabatic expansion, in kj.