s = 2 + 7 cos t Find the body's velocity at time t = π/3 sec.

Question

The equation gives the position s = f(t) of a body moving on a coordinate line (s in meters, t in seconds).

s = 2 + 7 cos t

Find the body's velocity at time t = π/3 sec.

MULTIPLE CHOICE

- 7/2 m/sec

7/2 m/sec

7√(3)/2 m/sec

- 7√(3)/2 m/sec

Answer 1

v(t)=-7sin(t)

v(pi/3)=-7sin(pi/3)

v(t)=-(7sqrt(3))/2 m/sec