Question

If the force is f=-30 units and the acceleration is a=6 units, find the mass, m

Answer 1

According to Newton's law:
Force = mass * acceleration
The force is given as -30 units (the negative sign only indicates the direction)
The acceleration is given as 6 units

Substitute is the above equation to get the mass as follows:
30 = 6*mass
mass = 30/6 = 5 units