Question

Jamie owns a sailboat rental company, which has a large variety of sailboats of different sizes. He observed that the speed of the sailboat (with the wind) largely depends on the length of the sailboat, and is approximately one and a half times the square root of its length. Which of the following options represents the relationship between length and speed of a sailboat?

Answer 1

Answer:C

Explanation:

Formula must be S(x) = (1+1/2)√x = 1.5√x, eliminating A and D. Diagram must show that a zero length boat doesn't move, and that boat length four feet goes 1.5×2 = 3 knots. That eliminates B. Check: C says zero feet goes zero knows and 4 feet goes 3 knots.

Answer 2

Graph C

Explanation:

We know the speed is equal to one and a half times the square root of the length. This means that speed is the dependent variable (y), and length is the independent variable (x).

Since the speed, S(x), is 1.5 times the square root of the length (x), we get the function

S(x) = 1.5√x.

When x = 0, S(x) = 1.5√0 = 1.5(0) = 0. This makes it graph C.