If the pitch of the sound coming out from a speaker increases, which is true about the sound wave?

(a)wavelength increases
(b)wavelength decreases
(c)amplitude increases
(d)amplitude decreases

What is the final velocity of the initial velocity of 25 and -50?

The diagram shows a series of volcanic island and a hot spot determine the direction of movement of the tectonic plate that for the island

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.