The net Force on an object is 10 N and its acceleration is 2 m/s2, what is its mass?

By Newton's second law, the net force acging upon a moving body is equal to the mass of the body times the acceleration of the body. Thus, F=ma. With a known force and acceleration, this is just a simple algebra step. I will use capital M for mass to prevent unit confusion.

F = M a

10N = M (2m/s^2)

5Ns^2/m = M

As a newton is defined as:

N = kgm/s^2

5Ns^2/m = 5kg

=> The mass of the body is 5 kilograms.