A particle moves along the x-axis so that its position at anytime t>= 0 is given by the function x(t)=t^3-12t+2 where x is measured in feet and t is measured in seconds.

Question

A Find the displacement during the first 3 seconds. In which direction did the particle move? B At what value(s) of t does the particle change direction? Explain your reasoning. C When does the particle speed up? Justify your answer.

Answer 1

So Nandini B.,

You are at the "origin" on this problem?? To find a displacement, calculate the position at the two specified times, and subtract the initial from the final. Works every time!

The particle changes direction when what physics variable has a certain value? You should know that, or be able to figure it out. So do your first derivative, and solve the equation.

-- Cheers, --Mr. d.