Read the excerpt from Team Moon. The trouble with option 2 was that the venting might push the fuel to an unstable condition. Or, another possible outcome of the “burping”: what if the landing gear hadn’t deployed correctly? Could any movement, or any resulting burst—no matter how small—tip the LM over? Many a voice in the debate thought the safest option was to abort—now! But that opinion was quickly overruled by the Grumman and NASA leadership (who were confident of the landing gear), and the consensus of the leaders was that it would be safe to gently, gently burp the engine.

Which detail from the excerpt identifies a solution?

the venting might push the fuel to an unstable condition
that opinion was quickly overruled by the Grumman
what if the landing gear hadn’t deployed correctly
it would be safe to gently, gently burp the engine

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?