67.Determine the average time to cut by automatic oxy-acetylene (machine) crosswise a 4 ft x 8ft. x 4 in thick steel plate. (Oxy acetylene cutting speed = 9 inches per minute).a.6.85 min b.318 sec (ans)
68.Computes for the induced/compressive stress, in Kpa, of a steel solid shafting of 50 mmdiameter and 800 mm in length that is subjected to an increase of temperature by 80 deg. C.Use k for steel = 0.0000119 m/m-°C. (E=30,000,000 psi = 206,768 Mpa).
69.A mass weighing 56 lbs. Rests on horizontal surface. The force needed to move along thesurface is 20 lbs. Determine the coefficient of friction.
70.Determine the time in seconds, to saw a rectangular magnesium bar 5 in. wide and 2 in. thickif the length of cut is 5 in. The power hacksaw does 120 strokes/min and the feed/stroke is0.127 mm.
71.A car travels with an initial velocity of 10 m/sec or 36 km/hr. If it is decelerating at a rate of 3m/sec-sec, how far, in meters, does it travel before stopping?