Question #3df20

1 Answer
Jan 20, 2017

See below.

Explanation:

The weight of a stationary object near the surface of the earth is equal the product of the mass of the object and the gravitational (free-fall) acceleration constant, gg. This is equal in magnitude to the force of gravity.

W=vecF_g=mgW=Fg=mg

Where WW is the weight.

Weight is a force and can be given in newtons, where a newton is equivalent to one kilogram meter per square second:

1 N= (1kgm)/s^21N=1kgms2

If using newtons, the mass of the object should be in kilograms. The gravitational acceleration constant, gg, is equal to 9.8m/s^29.8ms2. So, if we are calculating the weight of a stationary object on Earth we would have units:

W=mg=kg*(m/s^2)W=mg=kg(ms2)

=>(kgm)/s^2kgms2

So, you should get units of newtons, NN.

Multiplying kg*N/(kg)kgNkg would get you the correct units. The difference is that this expresses the units of acceleration as N/(kg)Nkg, which is equivalent to ((kgm)/s^2)/(kg)=m/s^2kgms2kg=ms2. It is not incorrect.