The equation of a transverse wave is
y(x, t) = 0.02 cos(10(pi)x - 400(pi)t)
where the units are SI. The velocity of the wave is
a. 0.20(pi)m/s
b. 8(pi)m/s
C. 40 m/s
d. 0.20 km/s
e. 0.40(pi)km/s