Physics A.2 Forces and Momentum

Linear momentum

the product of an object’s mass and its velocity. A vector quantity

Impulse

Impulse is the change in momentum of an object.

Elastic collision

a collision in which both momentum and kinetic energy are conserved.

Inelastic collision

a collision in which momentum is conserved but kinetic energy is not.

Centripetal acceleration

acceleration experienced by an object moving in a circular path.

Newton’s 1st law of motion

An object at rest stays at rest and an object in motion stays in motion unless acted upon by a net force.

Newton’s 2nd law of motion

The net force acting on an object is equal to the mass of the object multiplied by its acceleration.

Newton’s 3rd law of motion

For every force acting on A by B, there is an equal magnitude and opposite direction of force acting on B by A.

Force

a vector quantity that can change the state of motion of an object.

Normal force

a contact force that acts perpendicular to the surface of contact.

Frictional force

a contact force that acts parallel to the surface of contact.

Elastic restoring force

a force that acts to restore a deformed elastic object to its original shape.

Viscous drag force

opposes the motion of an object through a fluid.

Buoyancy

an upward force exerted on an object immersed in a fluid.

Magnetic force

the force experienced by a moving charge or a current-carrying conductor in a magnetic field.