# Finding relativistic force in terms of acceleration

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1. Oct 21, 2015

### SquidgyGuff

1. The problem statement, all variables and given/known data
The instantaneous force F acting on a particle, as measured in frame S, is
Use the formula for the linear momentum ( ) in and the definition of the acceleration a to show that

3. The attempt at a solution
The professor said that this required use of programs such as mathematica in order ot solve, however, I can't figure out a way to solve this, I can derive the force transformation in to another inertial reference frame, but the equation needs to be in terms of acceleration in the S frame, not the S' frame. I just need to know where to start with this.

2. Oct 21, 2015

### Geofleur

It looks like you will need to treat $\mathbf{u}$ and its magnitude as functions of $t$ and take the time derivative of the expression given for $\mathbf{p}$.

3. Oct 21, 2015

### SquidgyGuff

Is there anyway to do this without expressing u in terms of t? In the prevoud question I found the velocity transformation as follows: