If the value of force calculated from the moomentum equation

If the value of force calculated from the moomentum equation is negative, what does it mean?

Solution

Momentum equation states that the sum of forces acting on the system considered is equal to the change in momentum with respect to the assumed coordinate axes.

So, if the unknown in the above equation is the force. assume a specific direction for the force and then substitue the value of the force in the momentum direction.

If then the force obtained from the momentum equation is negative, this means the assumed force direction must be reversed. this has no effect on the magnitude of the force.