What is the change in internal energy of a system that takes in 3.88 106 J of heat, and does 4.50 105 J of work while dissipating 7.92 106 J of heat

ΔU = -4.904 × 10^(5) J

Explanation:

We are given;

Heat transfer into the system;Q1 = 3.88 × 10^(6) J

Heat transfer out of the system;Q2 = 7.92 × 10^(6) J

Work done; W = 4.5 × 10^(5) J

Now, the net heat transfer is the heat transfer into the system minus the heat transfer out of the system. Thus;. Q = Q1 - Q2

Q = (3.88 × 10^(6)) - (7.92 × 10^(6))

Q = -4.04 × 10^(6) J

The formula for change in internal energy is given by the first law of thermodynamics:

ΔU = Q - W

ΔU = (-4.04 × 10^(6)) - 4.5 × 10^(5)

ΔU = -4.904 × 10^(5) J

The negative sign means loss of internal energy

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.

conservation of mass

mass before something happens = mass afterwards