If the speed of the ball at the bottom of the circle is v, what is the expression for the centripetal force on the ball in terms
of its speed v and the length L of the string? Take the upward direction as positive and the downward direction as negative when considering the sign of the forces. (Use the following as necessary: m, v and L.)
Since there is a flat rate of 15, that is your y-intercept. The $3 charge is variable and depends on the number of days, so that would represent your slope.
No Tom is not correct as the simplest form for the sum of 5/12 and 1/12 is not 6/12. This can still be simplified by 6 and that would give you 1/2 as the most simplified answer.