The wall of a building measures 8 m horizontally by 3 m vertically, and consists of 250- mm-thick concrete. on the inside it is covered with 140-mm-thick extruded polystyrene insulation. the wall has a 1.4 m × 1.0 m door of 12-mm-thick plywood with no insulation. outside and inside air temperatures are -5°c and 18°c, respectively. the corresponding convection heat transfer coefficients are 38 w m2 k-1 and 7 m-2k-1. calculate the rate of 1151 (a) heat transfer through the wall

answer: 0

explanation: im   14

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.

this would be about 43%