# Object traveling straight line...

• Oct 3rd 2006, 07:01 PM
becky
Object traveling straight line...
The position s(t) of an object moving along a straight line is given. Find object's velocity and acceleration and all times where acceleration is 0.

s(t) = 3t^5 - 5t^3 - 7
velocity = s'(t) = 15t^4 - 15t^2
acceleration = s''(t) = 60t^3 - 30t

0=60t^3 - 30t
0=30t(2t^2 -1)
0=t and
0=2t^2 - 1
1=2t^2
1/2 = t^2
square root of 1/2 = t

Hmmmm....I doubt the last part.
• Oct 3rd 2006, 08:02 PM
ThePerfectHacker
Quote:

Originally Posted by becky
The position s(t) of an object moving along a straight line is given. Find object's velocity and acceleration and all times where acceleration is 0.

s(t) = 3t^5 - 5t^3 - 7
velocity = s'(t) = 15t^4 - 15t^2
acceleration = s''(t) = 60t^3 - 30t

0=60t^3 - 30t
0=30t(2t^2 -1)
0=t and
0=2t^2 - 1
1=2t^2
1/2 = t^2
square root of 1/2 = t

Hmmmm....I doubt the last part.

It doth not hurt my gaze.*)

*)Translation. Correct.
• Oct 3rd 2006, 08:12 PM
becky
Happy Dance Of Thanks
It's correct - never expected you to say that.
Happy Dance and Marquaritas for everyone....

Quote:

Originally Posted by ThePerfectHacker
It doth not hurt my gaze.*)

*)Translation. Correct.