An electromagnetic wave traveling through a vacuum has a wavelength of .15 meter. what is the period of this electromagnetic wave?

Ajet plane has a sound level of 120 db at a distance of 60 m. what is the q23. sound level at a distance of 6.0 km? (60)2 (6000)? om solution 80db db, hint: 16x assume ultrasound waves travel through the body of an animal at 1540 q24. m/s. if a 30,000 hz signal were reflected off a portion of a heart which was moving toward the source at 3 m/s, what frequency signal would return to the stationary source? solution 30.117hz

Ababy stroller is a rest on top of a hill which is 10 m high. the stroller and baby have a mass of 20 kg. what is the potential energy of the baby and stroller?

Which changes of state do the labels represent? a: b: c: