A 100 Hz sinusoidal wave is travelling in the positive x -direction along a string with a linear mass density of 3.5×10−3 kg/m and a tension of 35 N. At time t=0 , the point x=0 , has maximum displacement in the positive y -direction. Next when this point has zero displacement, the slope of the string is π/20 . Which of the following expression represent (s) the displacement of string as a function of x (in metre) and t (in second)
a. y=0.025cos(200πt−2πx)
b. y=0.5cos(200πt−2πx)
c. y=0.025cos(100πt−10πx)
d. y=0.5cos(100πt−10πx)