The figure shows the displacement y versus time t of the point on a string at x = 0, as a wave passes through that point. The scale of the x axis is set by ys = 84.0 mm.The wave has form y(x, t) = ym sin (kx - ωt+φ). What is φ? (Caution: A calculator does not always give the proper inverse trig function, so check your answer by substituting it and an assumed value of ω into y(x, t) and then plotting the function.)
y(x, t) = ym sin (kx - ωt+φ)
The Attempt at a Solution
This is supposed to be really easy but the solution I got was wrong. My approach was straight forward:
read off the initial y value --- y(0,0)=0.028
and sub in the equation: 0.028=0.084sin(0-0+φ)
The question mentioned that the calculator might give the wrong value but I do not see how I could make amend to it.
Please enlighten me!