What is the mass of an object in freefall?

Question

I only know the acceleration of gravity, down, and the object is in kinetic equilibrium. A force of 125 Lbs is pushing the object up, vertically. I want to know the mass of the object. What can I do?

Answer 1

If the object is in equilibrium, then the force of gravity is equal to the wind resistance force, both 125 lbs.

This means the weight of the object is 125 lbs, but you need to know the force/strength of gravity to get the mass of the object.

On earth, the mass would be 125 lbs.

Answer 2

Suppose that an elephant and a feather are dropped off a very tall building from the same height at the same time. Suppose also that air resistance could somehow be eliminated such that neither the elephant nor the feather would experience any air drag during the course of their fall. Which object - the elephant or the feather - will hit the ground first? The animation at the right accurately depicts this situation. The motion of the elephant and the feather in the absence of air resistance is shown. Further, the acceleration of each object is represented by a vector arrow.

Many people are surprised by the fact that in the absence of air resistance, the elephant and the feather strike the ground at the same time. Why is this so? This question is the source of much confusion (as well as a variety of misconceptions). Test your understanding by making an effort to identify the following statements as being either true or false.

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Answer 3

well the trickiest part is converting the upward force to SI units. consider the statement that the acceleration due to gravity is known and we have the statement that it is in equilibrium thus Force down = Force up thus devide force up by the acceleration due to gravity and you'll have the mass of the object