The position of an object moving along a line is given by p(t) = 2t - tsin(( pi )/4t) . What is the speed of the object at t = 7 ?

1 Answer
Jun 3, 2016

v(7)=-1.117

Explanation:

p(t)=2t-t sin (pi/4 t)" the equation of object's position"

v(t)=d/(d t)p(t)=d/(d t) (2t-t sin(pi/4 t))

v(t)=2-[sin(pi/4 t)+t*pi/4 cos(pi/4t)]

v(7)=2-[sin(pi/4*7)+7*pi/4cos(pi/4*7)]

v(7)=2-[-0.707+7*pi/4 *0.707]

v(7)=2-[-0.707+3.887]

v(7)=2-3.117

v(7)=-1.117