Given an advanced sinusoidal wave to the left of the string, with an amplitude of 1.4 cm, a wavelength of 40 cm, and a frequency of 20 Hz. It is known that at time t = 0 at point 0 = x the copy is reset and the string moves upwards.
A. Write the function that describes the copy of each point X in the string as a function of time t. Express using the variables x, t, and the numerical data in question. Write down the units of each number.
B. Calculate the velocity of the point at the beginning of the axes at time t = 0.
C. What is the copy at point x = 5 cm at time t = 3 sec?