Question

What is the mass of the object whose weight is 45N?

Answer 1

Weight is a force that is directed towards the center of the earth, and is equivalent to mass by gravity.
F = mg
Assuming that the body is on the earth and knowing that the value of the earth's gravity is equivalent to 10 m / s ^ 2.
Thus
m = F / g = 45/10 = 4.5 Kg, it would be the respective mass of the body