Particle Position and Momentary Stop: Solving a Motion Equation

[einsteinphysi]

Homework Statement

A particle's position is given by x = 3.00 - 12.00t + 3t2, in which x is in meters and t is in seconds. Where is the particle when it momentarily stops?

Homework Equations

The Attempt at a Solution

I tried plugging in m and s, like m= 3 - 12s +3s^2 and tried to solve for s but hit a dead end

 

[einsteinphysi]

I know I'm probably doing it dead-wrong, though.

 

[SteamKing]

What is the velocity of the particle when it stops?

 

[SteamKing]

To reply to your attempted solution, why would you substitute 'm' for x and 's' for t?
'm' and 's' are the units of the time variable t and the position variable x.

 

[einsteinphysi]

What is the velocity of the particle when it stops?

I don't want to answer but can you give me a hint as to how I would find that?
Well, if it's stopped...0?

 

[einsteinphysi]

x = 3.00 - 12.00t + 3t2
v= 12 +6t?

 

[einsteinphysi]

a=6?

 

[raymo39]

ok so you have a function that describes the velocity (v = 12 + 6t) and you have a value for the velocity that you want to know what time it occurs at...

 

[einsteinphysi]

ok so you have a function that describes the velocity (v = 12 + 6t) and you have a value for the velocity that you want to know what time it occurs at...

So plug in 0 for v? 0=12 + 6t
-2=t?

 

[einsteinphysi]

When I then plug -2 into original? 39?

 

[einsteinphysi]

HAHA, I see a mistake (when I took the derivative).
v=-12 + 6t
0=-12 + 6t
2=t

 

[einsteinphysi]

Now what?

 

[einsteinphysi]

Got it!

 

[raymo39]

well done! :)