Simple Acceleration and Velocity Problem

[veronicak5678]

Homework Statement

A train travels along a straight track. Its position is given by x(t) = At^3 + Bt from t = 0 to t=5.0 s.
a- find an expression for the velocity.
b- find an expression for the acceleration.
c- if the train has an acceleration of 2.00 m/s^2 and a velocity of 10.0 m/s at t=5, find 'A' and 'B'.

Homework Equations

v= dx/dt

a = dv/dt

The Attempt at a Solution

I got 3At^2 + B for velocity and 6At for acceleration. I got (1/15) for 'A' and 5 for 'B'. I don't have a book yet and just wanted to make sure i understand what I'm doing. Any help would be appreciated!

 

[Kurdt]

Looks good to me.

 

[veronicak5678]

Sorry, I don't know what you mean...

 

[LowlyPion]

Sorry, I don't know what you mean...

No you did it right. I made a hasty math mistake.

 

[veronicak5678]

Great. Thanks for your help!

 

[Kurdt]

I'm saying your answers are correct.

EDIT: methinks I missed something here