Arod of length 1.2 m has non uniform linear mass density rho_li(x) in kilograms per meter given by rho_l(x) = a + bx^3, where x is the distance in meters from the left end of the rod. (a)what are the si units of a and b? (b) find the total mass of the rod if a = 2 and b = +5. (c)find the position of center of mass of the rod.

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.