How do you find the mass of an object suspended in gravity?

Answer 1

An ordinary balance scale would work IF you were in a vessel designed to simulate gravity by rotating, so that objects in contact with the inside of the rotating surface would be pressed against it. [Or if you were experiencing a constant change of velocity] If you didn't have that available, you could use some kind of "sling" balance which would not be difficult to build (but maybe tricky to use safely). You could also take an object of known mass and fire it at the object of known mass. Analyzing the way the unknown mass responds will give you its mass.

Incidentally, if you were on the inner surface of a huge cylinder in a zero gravity environment and the cylinder were rotating to simulate gravity, you would probably have the experience of watching objects seemingly fly in circles around the inside of the cylinder, causing quite a hazard. The rotating cylinder is not actually creating a gravity field inside. Objects hanging freely in the interior of the cylinder will continue to do so (making them appear to fly in circles) until and unless they come in contact with the inner surface or something already in contact with the inner surface.

Good as those answers may be, the question itself is flawed as there is no thing as truly zero gravity, no matter how far away you get from an object its gravity still technically affects you, it simply gets closer and closer to zero without ever actually reaching it, much as an asymptote on a graph. This is because force due to gravity equals G(m1m2/r2). As the m's equals the masses of the two objects, r is the distance, and G is a constant, there is nothing in this equation that allows gravity to equal zero unless one of the masses is zero which would defeat the purpose as one of the objects would not exist (unless your discussing particles that randomly appear and disappear in vacuum but that's getting a bit specific...that was a attempt at a joke, ha ha...

Answer 2

You first have to derive Newton's law of universal gravitation from F=ma. The result of this is:

F = G x (m1 x m2)/d2

where G= Newton's Gravitational Constant = 6.673E-11 Nm2kg-2

m1 and m2 = the masses of two objects (kg)

d = the distance between there centers (m)

By simply taking the earth as one of the masses and a human as the other, the force due to gravity can be calculated.

Then by using F=ma the acceleration due to gravity can be calculated by dividing the force by the human's mass. This should produce the known value of 9.81 ms-2.

Answer 3

The silly answere is, "Weigh it".

However, I suspect that the question is about a mass which is in free-fall, and therefore has no measurable weight. The mass might be measured by finding out how it accelerates.

Simply, we fix the mass to a wall. Then we attach a spring to it and stretch the spring to a certain distance. Then we release the mass from the wall and time how long it takes to go a given distance, subject to the pull of the spring. As we know the force of the spring at every point of the journey and the time of the journey, using acceleration and velocity equations we can work out the mass.

Answer 4

You can measure the mass in different ways; which method is more appropriate depends on the circumstances:

• By the object's weight. This weight is divided by the gravitational field, to obtain the mass.
• By an object's resistance to acceleration. Use Newton's Second Law.
• By an object's gravitational attraction of other bodies. Observe the acceleration of the other object, and use the universal law of gravitation.

Answer 5

w=mg. weight is the product of mass and gravity

Answer 6

Weight is the pull exerted by gravity on a mass. On Earth, as gravity is defined as unity, an objects mass is also its weight.

On other planets, this will not be the case.