MUSCULAR FORCE AND FRICTION FORCE

  When we breathe in and exchange of air air to breathe, it also includes the force of the muscles and the beating of wet ego is due to the strength of the muscles produced by the heart muscle.  Animals such as bulls, camels and horses provide their own body strength and help man working hard.  For example, the bull pulls H using the force of his muscles.  Similarly, a horse and a camel exert such force in pulling carts.  An elephant pulls a heavy log of oad using muscular force.  And in the Arctic regions (snow-bound ns), reindeer pulled sleds (wheel less vehicles) using their cellar force.  Muscle force can be applied to an object only when the body of our animal) is in contact with the object, so n force is a contact force.  For example, when we lift a book with muscular force, our hand is attached to the guess.  14. The muscle cannot toss the book without touching it from the table.  Our contact with an animal can be t) with an object to exert muscle force, for example through a stick or even a piece, when we hit a hockey ball,  We apply muscle power to the ball through hockey and when we pull a bucket of water from a well, then we put the collection force into the cart through a rope.  Advertisement in bucket). 

 Pietional Force (or friction) A ball moving on the ground slowly slows down and stops after traveling some distance.  We know that a force is used to stop a moving body.  This means that a force is applied to the NG ball from the ground which opposes its motion and stops it.  This force which opposes the motion of the ball is known as the force of friction.  We can now define the force of friction in such a way that the force always opposes the motion of one body to another which is called friction force tor.  Oblique acts force between two surfaces that are in contact with each other.  

A ball moving on the ground slows down and then stops due to the force of friction and bends the ball.  In this case the two surfaces in contact are the ground surface and the ball surface.  The friction force HOwn is also known as the 'force of friction' or simply 'friction'.  Now we will give some more evidence from everyday life.  As61 ti we stop the bicycle running.  It slowly slows down and stops after covering some tnce.  

The bicycle moving on the road slows down and eventually stops due to the frictional force of the bicycle and the road tire.  This frictional force opposes the speed of the bicycle and brings DA stop.  In this case, the two surface ah rba this is a tume of victorys in contact are the road surface and D's tire surface.  Likewise, a car or scooter moving on the road comes to rest (or stop) due to the force of friction when the famine is switched off.   

When we stop a boat that runs in water, it slows down and then the boat entry into the water stops and eventually stops due to the force of friction between the boat and the water.  The tap force exerted by the water opposes the boat's motion and stops it, in which case the two surfaces are the surface of the boat and the surface of the water.  E The force of friction (or force of friction) always acts on all moving objects, and its direction is opposite to the direction of motion.  Since the force of friction arises only when the surfaces of two s are in contact with each other, therefore, the force of friction is an example of a contact force.  se Note that it is not necessary that an agent exerting an object must always accompany it.  There are some forces that act even remotely on an object.  We will now discuss non-contact forces.