The position of an object moving along a line is given by p(t) = 7t - cos(( pi )/3t) + 2 . What is the speed of the object at t = 8 ?

1 Answer
Jan 23, 2017

7.907 m/s

Explanation:

Speed is the magnitude of velocity. Velocity is the change in position. p'(t)=v(t)

p(t)=7t-cos(pi/3t)+2 => p'(t)=v(t)=7+pi/3sin(pi/3t)

at t=8 we have v(8)=7+pi/3sin(pi/3(8))=7+pi/3sin((2pi)/3)=7+pi/3(sqrt(3)/2)=7+(sqrt(3)pi)/6approx7.907m/s