2. Newton's laws of motion state the relationship
between a body and the forces acting upon it, and
its motion in response to the forces.
There are three laws of motion which were compiled
by Isaac Newton.
3. An object either remains at rest or continues
to move at a constant velocity, unless acted
upon by an external force.
Newton's first law of motion is also known
as the Law of Inertia.
4. The vector sum of the forces F on an object
is equal to the mass m of that object
multiplied by the acceleration vector a of
the object.
Newton's second law of motion is known as
the Law of Acceleration
5. When one body exerts a force on a second
body, the second body simultaneously
exerts a force equal in magnitude and
opposite in direction on the first body.
Newton's third law of motion which is
known as the Law of Action and Reaction.
6. Newton's first law
As per the law, if the net force is zero, then the velocity
of the object is constant.
Velocity is a vector quantity which represents both the
object's speed and the direction of its motion
The statement that the object's velocity is constant is a
statement that both its speed and the direction of its
motion are constant.
The first law can be stated mathematically as
Σ F = 0 => dV/dt = 0
7. Newton's second law
As per the law the net force on an object is equal
to the rate of change of its linear momentum.
F = m(dV/dt) = ma
where F is the net force applied, m is the mass of
the body, and a is the body's acceleration.
8. Newton's third law
As per the law all forces exist in pairs: if one
object A exerts a force FA on a second object B,
then B simultaneously exerts a force FB on A,
and the two forces are equal and opposite:
FA = −FB
9. These three laws are excellent approximations
at the macro scales and speeds of everyday life.
However, Newton's laws are inappropriate for
use in certain situations like
- at very small scales
- very high speeds
- very strong gravitational fields
Newton’s laws are very helpful to understand
physics concepts.
