What happens to the total mass of a substance undergoing a physical change?

Can somebody explain to me how newton's 3rd law relates to momentum? ~ap physics 1

We put a force of 50n on an object and the acceleration is 100 m/s². what is the mass of the object?

The precision of a laboratory instrument is ± 0.05 g. the accepted value for your measurement is 7.92 g. which measurements are in the accepted range? check all that apply. 7.85 g 7.89 g 7.91 g 7.97 g 7.99 g