Motion and momentum

Newton’s first law of motion states that…

An object will remain at rest or continue to move unless acted on by a resultant force

If an objects velocity changes…

A resultant force must be acting on the object

A velocity changes when…

It’s speed or direction changes

Newton’s third law of motion states that…

When two objects interact, they exert equal and opposite forces on each other

Electrons have a negative charge; they exert an…

Electrostatic repulsive force on each other

In Newton’s third law you never see…

Both forces acting on the same object

The four fundamental forces are:

Gravitational

Electromagnetic

Strong nuclear

Weak nuclear

When you push your hands together the contact force you feel is due to…

The electrostatic repulsive forces between the electron clouds around the atomic nuclei in your hands

Newton’s second law states…

The net force acting on an object is directly proportional to the rate of change of its momentum, and is in the same direction

Momentum is always…

Conserved

The linear momentum of an object depends on its…

Mass and its velocity

The SI unit of momentum is…

Kilogram metres per second

Momentum is a ____ quantity

Vector

When two or more objects collide or interact, the objects transfer kinetic energy and momentum between themselves, but…

The total momentum doesn’t change, provided that no external forces act on the interacting objects

The principle of conservation is expressed as follows…

When objects collide, the total momentum before and after the collision is the same

Zero momentum occurs when…

The momentum of the two objects have the same magnitude but in different directions

A good way to investigate momentum would be by using a linear…

Air track

A linear air track minimises…

Friction

In an elastic collision…

Momentum is conserved, total energy is conserved, kinetic energy is conserved

In an inelastic collision…

Momentum is conserved, total energy is conserved, kinetic energy is not conserved

The impulse of a force is equal to…

The change in momentum

On a force-time graph…

The impulse is the area under the graph