# Particle potential energy - acceleration?

1. Mar 8, 2016

### reminiscent

1. The problem statement, all variables and given/known data

2. Relevant equations
ΔU = Uf - Ui

3. The attempt at a solution
Would I have to make the left side of the equation equal to m*a*x? Is the x on the left side equal to -100 m?

2. Mar 8, 2016

### Staff: Mentor

What's the formal relationship between force and potential energy?

3. Mar 8, 2016

### reminiscent

The derivative of potential energy equals force (Fx = -dU/dx). So the derivative would turn it to be: -C/(x2). Then it's just plugging in from there, correct?

4. Mar 8, 2016

### reminiscent

For the acceleration, I got -0.0011 m/s^2. Does that seem too small?

5. Mar 8, 2016

### Staff: Mentor

The magnitude looks good but its sign is suspect. Check the details of your derivative.

6. Mar 8, 2016

### reminiscent

Why isn't it negative, though? Since Fx = -dU/dx, wouldn't it be Fx = -(-C*-1*x-2)? It will still be negative.

7. Mar 8, 2016

### Staff: Mentor

Oops. You're quite right. My mistake.