the position of a particle moing along a line is given by s(t)=2t^3-24t^2+90t+7 for t0. For what values of t is the speed of the particle increasing? I got t4, is this right?

Question

the position of a particle moing along a line is given by s(t)=2t^3-24t^2+90t+7 for t>0. For what values of t is the speed of the particle increasing? I got t>4, is this right?

anonymous · Answer

my friend got a different answer...but he just found the velocity and

amistre64 · Answer

define velocity :)   is negative velocity the same as positive velocity?  or velocity an absolute value?

amistre64 · Answer

velocity = the derivaive of the position equation;  so...

v(t) = 6t^2 -48t +90

amistre64 · Answer

this is a quadratic with an axis of symmetry at 48/2.6

48/12 = 4

so the slope increases at greater than 4..... so it slows down till it stops, then speeds up again after 4

amistre64 · Answer

in other words; t>4 is correct :)

anonymous · Answer

thanks