A wave is represented by
`y_1 = 10 cos (5x + 25 t)`
where, x is measured in meters and t in seconds. A second wave for which
`y_2 = 20 cos (5x + 25t + pi/3)`
interferes with the first wave. Deduce the amplitude and phase of the resultant wave.

Answer

A, B, C, D

Explanation

`A= sqrt((10)^2+(20)^2 +2(10)(20) cos 60^(@))`
= 26.46 cm

`tan phi = (20 sin 60^@)/ (10 + 20 cos 60^@)`
` = 0.866`
`:. phi = 40.89^@`
= `0.714` rad .