A0.14-kg apple falls off a tree branch that is 2.6 m above the thick grass. the apple sinks 0.067 m into the grass while stopping.
1) determine the average contact force that the grass alone exerts on the apple while stopping it. ignore air resistance.

The rigid beam is supported by the three suspender bars. bars ab and ef are made of aluminum and bar cd is made of steel. if each bar has a cross-sectional area of 450 mm2, determine the maximum value of p if the allowable stress is (σallow)st = 200 mpa for the steel and ( σallow)al = 150 mpa for the aluminum. est = 200 gpa and eal = 70 gpa.

What tightening torque should be used for a hexagonal head screw (not split-bolt) on a 250 kcmil conductor?

Based on the concept of the wave-like nature of light, huygens' theory of light postulates that the more light was "bent" by a substance the slower it would move while traversing across that substance. a) deflection b) interference c) refraction d) resonance