# Homework Help: Power associated with net force

1. Dec 5, 2015

### REVIANNA

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

How to prove :

$P*F_net=((dK)/(dt))$
i.e. power associated with the net force is the rate of change of kinetic energy.

3. The attempt at a solution

if I use the definition of power ans then that of work I get (m*a*ΔS )*(F_net)
further using F_net=ma
LHS= $m^2*a^2*ΔS$

There is no question along with it for which I could have though about the system and forces.
so I am assuming const force and acceleration.

2. Dec 5, 2015

### cnh1995

Is that product of force and power on LHS? If yes, the equation looks dimensionally incorrect.
Actually, if you solved dK/dt first, you'll get power.

Last edited: Dec 5, 2015
3. Dec 5, 2015

### REVIANNA

so sorry ,actually the F_net was written as the subscript P ,not their product
this makes complete sense now
$P_F=(dK/dt)$

4. Dec 5, 2015

### cnh1995

Then I believe answer is a couple of steps away. Good luck..