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

2 Answers
Dec 18, 2017

Answer:

#94ms^(-1)#

Explanation:

#p(t)=2t^3-2t+2#

to find the speed we differentiate

#p'(t)=6t^2-2#

for #t=2#

#p'(4)=6xx4^2-2#

speed#=94ms^(-1)#

SI units assumed

Dec 18, 2017

Answer:

The speed is #=94ms^-1#

Explanation:

The speed of an object is the derivative of the position.

#v(t)=(dp)/(dt)#

The position is

#p(t)=2t^3-2t+2#

The speed is

#v(t)=p'(t)=6t^2-2#

And when #t=4#

#v(4)=6*(4)^2-2=96-2=94ms^-1#