The position of an object moving along a line is given by p(t) = sin(2t- pi /4) +2 p(t)=sin(2tπ4)+2. What is the speed of the object at t = pi/3 t=π3?

1 Answer
Jul 17, 2017

The speed is =(sqrt6-sqrt2)/2=0.52=622=0.52

Explanation:

The speed is the derivative of the position

p(t)=sin(2t-pi/4)+2p(t)=sin(2tπ4)+2

v(t)=p'(t)=2cos(2t-pi/4)

When t=pi/3

v(pi/3)=2cos(2*pi/3-pi/4)

=2cos(2/3pi-1/4pi)

=2*(cos(2/3pi)*cos(pi/4)+sin(2/3pi)*sin(1/4pi))

=2*(-1/2*sqrt2/2+sqrt3/2*sqrt2/2)

=(sqrt6-sqrt2)/2=0.52