Physics

Problem

## Questions 9-10 A particle moves in a circle in such a way that the x and y -coordinates of its motion are given in meters as functions of time

t

in seconds by:

x=5 \cos (3 t) \quad y=5 \sin (3 t)

10. Which of the following is true of the speed of the particle? (A) It is always equal to

5 \mathrm{~m} / \mathrm{s}

. (B) It is always equal to

15 \mathrm{~m} / \mathrm{s}

. (C) It oscillates between 0 and

5 \mathrm{~m} / \mathrm{s}

. (D) It oscillates between 0 and

15 \mathrm{~m} / \mathrm{s}

. (E) It oscillates between 5 and

15 \mathrm{~m} / \mathrm{s}

(A) It is always equal to

5 \mathrm{~m} / \mathrm{s}

. (B) It is always equal to

15 \mathrm{~m} / \mathrm{s}

. (C) It oscillates between 0 and

5 \mathrm{~m} / \mathrm{s}

. (D) It oscillates between 0 and

15 \mathrm{~m} / \mathrm{s}

. (E) It oscillates between 5 and

15 \mathrm{~m} / \mathrm{s}