The position of an object moving along a line is given by p(t) = t-cos(( pi )/4t) p(t)=tcos(π4t). What is the speed of the object at t = 7 t=7?

1 Answer
Nov 19, 2017

The speed is =0.44ms^-1=0.44ms1

Explanation:

The speed is the derivative of the position

p(t)=t-cos(1/4pit)p(t)=tcos(14πt)

v(t)=p'(t)=1+1/4pisin(1/4pit)

Therefore,

When t=7s

v(7)=1+1/4pisin(1/4pixx7)=1+1/4pisin(7/4pi)

=0.44ms^-1