'Yank': A new term in biophysics

Biologists and biomedical engineers are proposing to define the term "yank" for changes in force over time, something that our muscles and nerves can feel and respond to.

Time-saving simulation of peeling graphene sheets

Control of atomic-scale friction and adhesion is critical for effective manipulation of the motion of nano- or micro-meter scale objects at interfaces. For example, in nanotechnology controlling adhesion during the peeling ...

Stretching proteins with magnetic tweezers

Physicists at LMU have developed a highly sensitive method for measuring the mechanical stability of protein conformations, and used it to monitor the early steps in the formation of blood clots.

How forecasters track Hurricane Dorian

The path of Hurricane Dorian, which is currently over the Atlantic and heading for the state of Florida, is closely monitored by US weather services with powerful forecasting tools.

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In physics, a force is any influence that causes an object to undergo a change in speed, a change in direction, or a change in shape. In other words, a force is that which can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate, or which can cause a flexible object to deform. Force can also be described by intuitive concepts such as a push or pull. A force has both magnitude and direction, making it a vector quantity. Newton's second law, F=ma, was originally formulated in slightly different, but equivalent terms: the original version states that the net force acting upon an object is equal to the rate at which its momentum changes.

Related concepts to force include: thrust, which increases the velocity of an object; drag, which decreases the velocity of an object; and torque which produces changes in rotational speed of an object. Forces which do not act uniformly on all parts of a body will also cause mechanical stresses, a technical term for influences which cause deformation of matter. While mechanical stress can remain embedded in a solid object, gradually deforming it, mechanical stress in a fluid determines changes in its pressure and volume.

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