Restoring force

The restoring force is a force, moving to a from the rest position, mass acts. The restoring force in this case acts towards the rest position of this mass, they want the mass " Reset " to its rest position.

It occurs, for example in deflections of elastic springs and in many cases leads to oscillations around the resting position. From restoring forces one speaks any of these spring commuting, commuting thread, oscillating water columns in U-tubes or leaf and torsion springs.

Restoring force for oscillations

In the absence or neglect of other forces applies: When you increase the displacement from the rest position, the restoring force causes a reduction in speed and when taking the deflection of an increase in speed. Due to the effectiveness of Newton's 2nd Law, the restoring force results in a positive or negative acceleration of the oscillating mass, respectively.

At the reversal points of the oscillation, the restoring force of each reaches its maximum value. On the zero crossings, i.e., while passing the rest position, the restoring force is equal to zero.

If the restoring force is directly proportional to the deflection, it is called a harmonic oscillation.

Example

Approximately true of the spring pendulum:

Fr = restoring force

D = spring constant

S = displacement

Note: The minus sign effect directed to the restoring force and the displacement of the pendulum in opposite directions. If one is interested only for the amounts of the variables involved, the minus sign can be omitted.