A. what is the change in internal energy if 500 j of heat is added to a system and 100 j of work is done by the system? show your work.

b. describe two sets of conditions of heat and work that cause a decrease in internal energy.

c. write one or two sentences describing how a heat pump works.

d. a neatly arranged closet is a very orderly system and has low entropy. why is it safe to assume that this did not happen naturally? write one or two sentences explaining your answer.

a) dU=Q-A, so DU=400 J

b) When you decrease heat while increase work and when you increase work while decreasing heat.

c) It takes heat from colder places and releases the heat to warmer places.

d) Because the order there is made by human.

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west