일반물리학 1 — Waves-I: Problem 44

44 The function \( y(x, t) = (15.0 \text{ cm}) \cos(\pi x - 15\pi t) \), with \( x \) in meters and \( t \) in seconds, describes a wave on a taut string. What is the transverse speed for a point on the string at an instant when that point has the displacement \( y = +6.00 \text{ cm} \)?