Forces and Motion
Forces and Motion is a principle of physics which examines the way in which objects move and interact. A force is a push or pull that might make an object change their movement and acceleration. Studying these concepts allows us to understand the working mechanisms of common things that take place around us from riding a bicycle to the movement of the planets.
1. Newton's Laws of Motion
First Law (Law of Inertia): Any object in rest remains at rest and an object in motion tends to maintain it's constant velocity unless it is moving under the influence of unbalanced forces. This law describes reasons why seatbelts will be important in cars.
Second Law: An object's acceleration depends on the net force acting on the object and mass. This relation is given by the equation F=mxa. It informs us about how much an object will accelerate when some force is applied.
Third Law: There is an equal and opposite reaction for every action. It means that Forces are always in pair. when you apply force on an object, it pushes back with the equal force and in opposite direction.
2. Gravity
The force that draws two bodies to each other is gravity. It confers weight to physical objects and makes them to fall when thrown in the earth. The magnitude of gravity depends on mass of the objects and the distance separating them.
3. Friction
Friction is the opposition experienced by any object that tries to move across another object. It retards or inhibits movement and it is why the objects eventually come to a stop when no other force is being applied. Friction is different with different surfaces.
4. Inertia
Inertia is the property of an object to oppose any kind of change in its state of motion. A body with a heavy mass has a higher inertia and it is difficult to bring such body into motion or stop it from moving. This idea has a direct connection with the first law of motion by Newton.