In August 1877, the American astronomer, Asaph Hall, discovered two moons orbiting Mars. He named them Deimos and Phobos, for the mythological sons of Ares, the Greek
counterpart of the Roman god, Mars. Phobos was the personification of panic. This
moon has a mass of 7.304 x 1014 slugs and orbits 3,700 miles above the surface of Mars.
Deimos was the personification of terror and dread. This moon has a mass of 1.0115 x
1014 slugs and orbits 12,470 miles above the surface of the red planet. Mars has a mass
of 4.397 x 1022 slugs and a radius of 2,106.1 miles. Determine the gravitational force
Mars exerts on Phobos.

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

Which one from below is not one of the reasons of planning failures? (clo3) a)-planner is careless. b-planner spend less time in the field but more time on the desk c)-planner is not qualified d)-planner does not have sufficient time to properly plan

Tom is having a problem with his washing machine. he notices that the machine vibrates violently at a frequency of 1500 rpm due to an unknown rotating unbalance. the machine is mounted on 4 springs each having a stiffness of 10 kn/m. tom wishes to add an undamped vibration absorber attached by a spring under the machine the machine working frequency ranges between 800 rpm to 2000 rpm and its total mass while loaded is assumed to be 80 kg. a) what should be the mass of the absorber added to the machine so that the natural frequency falls outside the working range? b) after a first trial of an absorber using a mass of 35 kg, the amplitude of the oscillation was found to be 10 cm. what is the value of the rotating unbalance? c) using me-3.5 kg. m, find the optimal absorber (by minimizing its mass). what would be the amplitude of the oscillation of the absorber?