The position of an object moving along a line is given by p(t) = 5t - cos(( pi )/3t) + 2 . What is the speed of the object at t = 13 ?

1 Answer
May 31, 2018

v(13) = 5+ pi/(2 sqrt(3)) " distance per unit time"

or

v(13) = 5.9 " distance per unit time"

Explanation:

The position function is given as

p(t) = 5t - cos(pi/3 t) + 2

We differentiate to obtain a velocity function

v(t) = 5 + pi/3 sin(pi/3 t)

Substitute t=13 to find the speed at this time

v(13) = 5+pi/3 sin(pi/3 (13))

which can be simplified to

v(13) = 5+ pi/(2 sqrt(3)) " distance per unit time"

or

v(13) = 5.9 " distance per unit time"