Force is that factor which is necessary to change the position and state of
a body. Laws of motion give the clear picture of force in following
manner:
(a) First law describes the importance of force in changing the state of a
body from rest to motion to or from motion to rest.
(b) Second law states that the force causes rate of change of velocity of a
body during motion.
(c) Third law describes how a body reacts against the force applied on it
and, consequently, moves forward.
Therefore, we can say that a force is push or a pull. According to Newton,
a force is something that has the ability to accelerate an object.
Remember, acceleration is not just limited to speeding up. It also
includes starting, stopping, slowing down, and changing direction.
Therefore, a force is something that causes an object to start, stop, speed
up, slow down, or change direction. The unit of measurement for force is
the Newton (N). One Newton of force is defined as the force required
accelerating a 1 kg mass at 1 m/s2.
Some important factors to consider when describing a force- are the
magnitude of the force, the point of application, and the direction that
force is being applied. We are able to represent force mathematically by
using a vector. A vector is a mathematical representation of anything that
is defined by its size and its direction. On paper a vector is represented
as an arrow. The length of the arrow represents the magnitude of the
force, the shaft of the arrow represents the line of application of the
force, and the arrowhead indicates its direction along the line of
application.
Forces may be classified in to the following forms:
(a) External Forces:
External forces are forces that act on an object as a result of its
interaction with the environment surrounding it. External forces can be
either contact or non-contact forces. Gravity is the only non-contact
force.
(b) Internal Forces:
Internal forces are forces that act within the body. Bones, muscles,
tendons, ligaments, cartilage, and other tissues exert forces on one
another.
(c) Force of Friction:
Friction acts between two surfaces of solid objects or rigid bodies in
contact and acts parallel to the contact surfaces.
Friction force is proportional to the normal contact force. As the normal
contact force is increased, the friction force is also proportionately
greater.
If two parallel forces are applied on bodies their combination may be
obtain by adding (if both are in same direction) or subtracting them (if
both are in opposite directions).If two non-parallel forces applied on a
body, their combination will be the resultant, a line joining head of the
force opposite to the body, to the tail of the force towards the body.
In my opinion, The Force is a very useful thing in life in general. Because any movement
that occurs in this life requires a force, and the force can also cause a change in the velocity
of a body that has mass (as well as the movement of stationary bodies), and this means the
acceleration of the body. Force is a vector quantity (has magnitude and direction),
measured in newtons and denoted by the symbol F , So The force is a push or pull and
affects our daily lives because without force, people would not be able to open and close
things or raise our arms or legs.... .or anything, for that matter.
Really, I had fun today while researching and reading about the force. Really, it is very
interesting and fun. I advise all of you to go and read about this wonderful topic. Also doing
experiments and measuring force when you produce it to push or move something is such
a fun thing. It is one of the most beautiful things that you will study and learn about from
my point of view.
The student or your brother: Kareem Elabasery.