If kilogram is added to kilogram then do we have a derived unit?

If you have a bowl with six apples and you take away four, how many do you have? anyone take a guess and post it. lol getting rid of my account might as well do it with some fun

10 newton object is placed 3 meters from the fulcrum. at what distance on the other side would you need to place a 15 newton object to balance the lever? show your work!

Air initially at 0.75 bar, 1000 k, and occupying a volume of 0.12 m^3 undergoes two processes. process 1-2: the air is compressed isothermally until the volume is halved. process 2-3: the air undergoes a constant pressure process until the volume is halved again. assume ideal gas behavior. a) determine the mass of the air, in kg. b) the work and the heat transfer for each of the two processes, in kj. (100 kj = 1 bar . m^3)