You have a lens whose focal length is 6.91 cm. you place an object on the axis of the lens at a distance of 11.1 cm from it. how far is the object\'s image from the lens?

First answer marked as brainiest which is the correct equation describing the first law of thermodynamics? a) when the internal energy of a system changes, it equals the amount of heat added plus the work done. b) when work is done by the piston, it is equal to the heat added plus the change in internal energy of the system. c) when heat is added to the system, it is equal to the amount of work done by the piston plus the change in internal energy of the system.