The air in a room measuring 8 ft x 9 ft x 12 ft is at 80 degrees fareinheight and 14.7 psig. What is the weight of the air in lbf? explain every step

Below question is from machine design. Please solve asap. You have to select bearings which are used to support a shaft, bearings are mounted at each end of shaft and 1.20 metre apart. A 600 mm diameter pulley is mounted at a distance of 300 mm to the right of left hand bearing and this drives a pulley directly below it with the help of belt having maximum tension of 2.25 kN. Another pulley 400 mm diameter is placed 200 mm to the left of right hand bearing and is driven with the help of electric motor and belt, which is placed horizontally to the right. The angle of contact for both pulleys is 180º and .Allowing working stress of shaft depends on the material you have selected for the shaft. Select the type of bearing mounted on both ends of shaft (either ball or roller bearing type and also elaborate the scenario for the selection of bearing).The Reliability Factor for Bearing may vary from 92% till 96%

The two gears in the picture below on the left are meshing together. The two gears in the picture on the right are stuck together and are on the same shaft. Which of these statements is true when the gears are turning? (There may be more than one correct answer). A. The two meshing gears have the same |?| B. The two gears on the same shaft have the same |?| C. The two meshing gears turn through the same magnitude of arc-length in the same time D. The two gears on the same shaft turn through the same magnitude of arc-length in the same time

State one word problem and solve it wherein the ideal mechanical advantage of a wedge is being solved. Use the formula, IMA = (Length of the Widge) divided by (Width of the Wedge). note: please do not forget to include your solution in solving the problem.