A radio antenna broadcasts a 1.0 MHz radio wave with 25 kW of power. Assume that the radiation is emitted uniformly in all directions. a. What is the waves intensity 30 km from the antenna? b. What is the electric field amplitude at this distance?
15.1 The Wave Model • Traveling wave Organized disturbance that travels with a well deﬁned wave speed • Mechanical waves Waves that involve motion of a substance through which they move the medium ‣ Medium of water wave: water ‣ Of sound: air ‣ Of stretched string is the string ‣ Causes displacement from Equilibrium Wave speed ‣ Speed with which a ripple moves across the water or pulse traveling down a string ‣ Wave transfers energy but the medium does not travel Electromagnetic and matter waves ‣ Electromagnetic don't require a material medium and travels through a vacuum ‣ Light travels through space transverse and longitudinal waves ‣ Transverse when