A farmer has to lift up a boulder 12 inches in the air in order to put it in his wagon. The boulder is 2000 bf. The farmer has the following tools available: a fixed pulley and a moveable pulley with a rope; an inclined plane with a length of 8 feet and a height of 12 inches; and a lever that is 10 feet long. The farmer has a maximum strength to push or pull 100 lbf.
Design a system using the tools the farmer has available to move or lift the boulder. Assume there is no friction and that mechanical advantage is ideal.
Calculate the ideal effort force that will be required by the farmer (must be less than 100 lbf)
Calculate the mechanical advantage of the individual mechanisms in the system and the total mechanical advantage of the system.

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false

Atank with constant volume contains 2.27 kg of a mixture of water phases (liquid-vapor). in the initial state the temperature and the quality are 127 °c and 0.6, respectively. the mixture is heated until the temperature of 160 oc is reached. illustrate the process in a t-v diagram. then, determine (1) the mass of the vapor in kg at the initial state, (2) the final pressure in kpa.

Acommercial grade cubical freezer, 4 m on a side, has a composite wall consisting of an exterior sheet of 5.0-mm thick plain carbon steel (kst= 60.5 w/m k), an intermediate layer of 100-mm thick polyurethane insulation (kins 0.02 w/m k), and an inner sheet of 5.0- mm thick aluminium alloy (kal polyurethane insulation and both metallic sheets are each characterized by a thermal contact resistance of r 2.5 x 104 m2 k/w. (a) what is the steady-state cooling load that must be maintained by the refrigerator under conditions for which the outer and inner surface temperatures are 25°c and -5°c, respectively? (b) for power saving purpose, which wall material should be increased/reduced in. thickness in order to reduce 50% of the cooling load found in part (a)? redesign the thickness of the proposed material. 177 w/m-k). adhesive interfaces between the q=575.93 w