(3) If a student varies a string's tension T and measures its wave velocity v, what regression analysis should be used to get the string's linear density u? What do the graph's slope and y-intercept mean and how can one read out from them?

A string of 1 m length clamped at both ends is plucked in the middle to generate a standing wave. Take the frequency of the first harmonic to be 10 Hz and the amplitude of the oscillations to be 2 cm. Consider the motion to be a simple harmonic one where appropriate.  Calculate the value of maximum velocity of up and down motion of the string at midpoint. Provide your anwser in m/s.

A ternary string is a string made up of Os, 1s, and 2s. How many ternary strings of length 11 are there?