Question

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

Answer 1

`p(t) = 2t - t^2cos(pi/3t)`

The speed is given as:

`v(t) = dotp(t) = 2+2pi/3tsin(pi/3t)`

so,

`v(5) = 2+(2pi)/3*5*sin((5pi)/3) ~~ 2 +(2pi)/3*5*(-0.87) = -7.11`