Force equation: use mass or weight?

[jbriggs444]

The English system does not recognize the pound mass

Yes, it does. The pound mass is the standard for commercial purposes.

Back when I went to school, my physics teachers and textbooks took great pains to say that the U.S. pound is always and exclusively a unit of force. Those teachers and textbooks were simply wrong. If you see packaged goods with a label such as "net weight 1 lb 2 oz", those are mass units and that net weight refers to a mass quantity.

 

[Digcoal]

I require to calculate acceleration of an object caused by a force of 100N acting upon it.
The weight of the object is 0.5kg
I'm using the equation

F = m * a

Is it correct to use weight of the object instead of mass in the equation.
Will it yield correct results?

Or would I need to calculate "mass" of the object first using the equation

m = W / g
where W is weight of the object and g is acceleration due to gravity.

F is the weight.
m is the mass.
a is the acceleration due to gravity.

In light of this, it will be less confusing for you if, when discussing weights and gravity, you use:

W = m * g

Your confusion arises because we have distinct concepts using the same terminology. People use kg for weight in everyday usage, when N is the more correct term for weight. Saying that I weigh 87kg is incorrect. I consist of 87kg of matter.

I weigh 950N on the Earth because gravity accelerates my mass of 87kg at 9.81 m/s^2 against the Earth.

I weigh 160N on the Moon because gravity accelerates my mass of 87kg (which stays the same) at 1.62 m/s^2 against the Moon.

 

[Herman Trivilino]

When you weight meat at the store on a spring scale, it measures force.

Those scales are calibrated, by law, to read what a physicist defines as mass. They do call it weight, as that is also required by law.