Ahot water stream of flow rate mh = 1 kg/s is to be cooled from 90°c to 60°c in a heat exchanger, by contact with a larger stream of cold water, mc = 2 kg/s. the inlet temperature of the cold stream is 40°c. calculate the heat exchanger area a needed for accomplishing this task. the overall heat transfer coefficient (based on a) is known, u = 100 w/(m2. k). consider first the counter-flow arrangement and later the cross-flow scheme in which two fluids are un-mixed

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.

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y

explanation:

wheres the pic