An object is falling at a rate that is 60 of the acceleratio

An object is falling at a rate that is 60% of the acceleration of gravity
therefore it is pressing down on anything below it with:

A> 100% of its mass

B> 60% of its mass

C> 140% of its mass

D> 40% of its mass

Solution

If N is the force pressing down, then -N is the exterior force pressing it up.
Applying Newton\'s second law in vertical direction, with downward direction as positive,
mg - N = ma
N = mg-ma = mg - 0.6mg = 0.4 mg

Answer: D