# Homework Help: Acceleration as a function of time

1. Sep 21, 2009

### halbe1

1. The problem statement, all variables and given/known data
A particle moves along the x axis. Its position as a function of time is given by x = 6.8t + 5.5t^{2}, where t is in seconds and x is in meters. What is the acceleration as a function of time?

2. Relevant equations

3. The attempt at a solution

2. Sep 21, 2009

### rock.freak667

how does acceleration relate to displacement?

OR how are are acceleration and velocity related?

Do this too.

3. Sep 21, 2009

### Simply Is

Here's a hint... you can find how to come up with your answer online... It requires BASIC calculus to solve...

Search for how velocity is related to displacement... then search how acceleration is related to velocity... It will tell you what you need to do to the equation you've got to get the answer...

Then do the math and you're done...

Hope this helped.

4. Sep 21, 2009

### halbe1

Well the slope of velocity is the acceleration.
I tried taking the derivative to find out the time and got 17.8....apparently that's wrong though.

5. Sep 21, 2009

### Simply Is

Your question isn't asking you for the time... It is asking for the acceleration as a function of time...

Function tells you that your answer will be an equation... not solution of the variable you have left. Go back to what you have before you solved for t.

6. Sep 21, 2009

### Larrytsai

double derivative
derivative of displacement=velocity
derivative of velocity=acceleration