[Marcella39]

When finding force of something can you use grams or do you have to convert to kg. Because I thought it had to be convertered to kg but my question only works out when I leave it in grams?

[Credendovidis]

Newton's 3rd law : When finding force of something can you use grams or do you have to convert to kg. Because I thought it had to be convertered to kg but my question only works out when I leave it in grams?

Newton's 3rd law : do you mean : Newton's Third Law of Motion??

That law refers to interaction of forces. You can use any meassure you prefer.
If you push the earth down with 80 Kg, the earth pushes you up with 80 Kg.
If you push the earth down with 80.000 g, the earth pushes you up with 80.000 g.

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[Credendovidis]

Note : if you meant anything else, just rephrase your post , and I'll try to answer it again !

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