# Strange kinematics problem [closed]

I've encountered a strange kinematics problem in a textbook.

Rest assured, I have long finished my studies in Physics, I simply decided to get back to the basics in order to refresh my skills.

The problem is the following:
"A particle is moving along the X-axis. The coordinate of the particle is changing with relation to time according to the law: $x = c_1t + c_2t^3$, where $c_1 = 2 m/s$, $c_2 = 1 m/s^3$.
Find:
a) The velocity and acceleration of the particle at a point of time = 2s
b) The mean velocity with which the particle travels in the first 3s"

The way I see it I can sort of unofficially take $c_2$ as the jerk, $c_1$ as the initial velocity and, maybe, the initial acceleration is = 0, even though nothing is mentioned about that. So the acceleration at 2s should be $2m/s^2$ and velocity should be $3m/s$ but the answer in the textbook is $v = 14m/s$ and $a = 12m/s^2$. I don't even want to talk about b).

I have no idea how this is supposed to be solved, one because I don't see any relevant information in the problem description and, two, because nothing like this was covered in the lesson of this problem.

## closed as off-topic by John Rennie, Bill N, stafusa, Kyle Kanos, Emilio PisantyOct 2 '17 at 18:39

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• "Homework-like questions should ask about a specific physics concept and show some effort to work through the problem. We want our questions to be useful to the broader community, and to future users. See our meta site for more guidance on how to edit your question to make it better" – John Rennie, Bill N, stafusa, Kyle Kanos, Emilio Pisanty
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• Calculus! mathgenius? – Bill N Oct 1 '17 at 16:44
• @BillN, the name is supposed to be ironic. – mathgenius Oct 1 '17 at 18:13
• Regardless of whether this is formal homework assigned to you by an instructor, our guidelines for homework and exercise questions apply. Please read them carefully. – Emilio Pisanty Oct 2 '17 at 18:39