Think of two toys rubbing. They get hot and scratch.
A lubricant is like a smooth slippery liquid that sits between them so they don’t fight.
It is a fluid made of long soft molecules that slide over each other very easily.
Imagine holding a ball up.
The Earth pulls it down like a magnet.
When the ball is high, it has stored energy.
This energy comes from gravity + height.
In the world of physics, two powerful and closely linked ideas describe how motion and force interact — momentum and impulse. Let us explore them in a clear and scientific way.
Momentum is the scientific term for the strength of motion an object possesses. It depends on two main factors — the mass of the object and its velocity.Mathematically, it is expressed as:
Momentum (p) = mass (m) × velocity (v)
Every moving object — from a drifting leaf to a speeding train — carries momentum.The greater the mass or the faster it moves, the larger its momentum becomes.
In simple terms, momentum tells us how hard it is to stop a moving object.A truck moving at the same speed as a bicycle will have far greater momentum, because it carries more mass.
In simple words, a force is a push or a pull . it is the reason things move, stop, speed up, or change direction.
Every movement we see — a bird flapping its wings, a car speeding on the road, or a rocket rising into the sky — happens because some force is acting.
Scientifically, force is what changes the motion of an object . it can make something start moving, stop moving, or change its speed.
The great scientist Sir Isaac Newton explained this in his famous Laws of Motion.He said, “An object will stay at rest or keep moving in a straight line unless a force acts upon it.”
That means — without force, nothing in the universe would ever change its motion.
How is momentum or impulse and different from speed and acceleration?