Stop moving after few seconds??

[Jeff]

You could loop through all your objects and set their velocities and angular velocities to zero.

for i in range (len(objects)):
	objects[i].setVelocity([0,0,0])
	objects[i].setAngularVelocity([0,0,0])

Start a timer when when the force is applied that will expire after 3 seconds then call your function that stops the movement.