Newtons laws of motion and momentum

What is Newton’s first law of motion?

An object will remain in a state of rest or constant velocity unless acted upon by an external force

What is Newton’s second law of motion?

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

What is Newton’s third law of motion?

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

Why don’t weight and the normal reaction constitute a Newtonian pair?

Because they both act on the same body and they are forces of different nature

What is the definition of impulse?

The average net force acting on an object multiplied by the time it acts on it

What is the area beneath a force against time graph?

The impulse

Is momentum vector or scalar?

Vector

What is the principle of conservation of momentum?

The principle of conservation of momentum states that the total momentum in a system remains unchanged unless there is an external force acting on it

How do we work out common velocity when two objects collide and stick together?

Momentum is conserved, so total initial momentum = total final momentum

What happens in a perfectly elastic collision?

Kinetic energy is conserved. Momentum is also conserved. After collision, objects are likely to move away from each other.

What is an example when we assume perfectly elastic?

Molecular motion

What happens in a perfectly inelastic collision?

Momentum is conserved. After collision, two objects tend to stick together and move at a common velocity