Question

If Shirley pushes one end of a desk to the right with a force of 12.0N and anfernee pushes the desk at the same time to the left with a force of 19.0N and the desk has a mass of 4.50kg. What is the net force on the desk?

Answer 1

The net force does not depend on the mass.

We have 12N to the right, and 19N to the left.
The net force is (19.0-12.0)N=7.0N to the left.