Free · Mechanics and material properties

Net Force from Mass & Signed Acceleration

Apply Newton’s second law along one axis, with signed force and acceleration and positive mass.

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Calculator inputs

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How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

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Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

A 2 kg mass accelerating at −3 m/s² has net force −6 N along the chosen positive axis.

Net force = mass × acceleration

Worked example

Enter these known values and leave the other values blank.

Mass
2 kg
Signed acceleration along one axis
-3 m/s²
Net force along the same axis
-6 N

Assumptions and limitations

  • Mass is positive and constant. This classical relationship is used in an inertial frame.
  • Force and acceleration are signed components along the same axis. The model does not add separate applied forces automatically.
  • At zero acceleration and force, mass cannot be uniquely inferred from their ratio.

Common questions

Can force be negative?

Yes. The sign identifies direction relative to the chosen positive axis.

Is this one applied force or net force?

It is the net force after all force components along that axis have been added.

References

One kip is exactly one thousand pound-force, using the international pound and standard gravity. Feet per second squared use exactly 0.3048 meters per second squared, replacing a rounded reciprocal factor. The pound-force uses the exact international pound and standard gravity instead of the rounded captured factor.

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