Awake on astring is described by the following equation y=(15cm)cos(3.14/5.0cm x_3.14/12s t.what is the amplitude of this wave?what is its wavelength?what is its period? What is its speed? In which direction does the wave travel
typo _ should be -
y = 15 cos [ (pi/5) x - (pi/12) t ]
= A cos [ 2 pi x/L - 2 pi t/T ] so a period when x = L or when t = T
A = 15 cm = 0.15 meter
goes one wavelength in one period so
pi/5 = 2 pi/L or 1/5 = 2/L
L = 10 cm = 0.10 meter
(pi/12) t = 2 pi t/T
1/12 = 2/T
T = 24 seconds
c T = L
c (24 seconds) = 0.15 meter
c = 0.15 meter/24 seconds = 15 cm/24s
minus sign moves right. As time increases x must increase to keep the argument of the cosine constant