(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A particle is trapped in a potential well described by U(x)= 1.8 x²-b where U is in joules, x is in meters, and b = 4.5 J.

Find the force on the particle when it's at x = 2.8m

Find the force on the particle when it's at x = 0 m

Find the force on the particle when it's at x = -1.4 m.

2. Relevant equations

F(x) = -dU(x) / dx

3. The attempt at a solution

so I just differentiated U(x), slapped a negative sign, and ended up with F(x) = 3.6x

Plugged in 2.8m, ended up with -10.08, and it ain't right. Any ideas why? I'm thinking itmighthave to do with the phrase "potential well".

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Force from potential equation

**Physics Forums | Science Articles, Homework Help, Discussion**