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Motion Physics
1. What is physics ?
A science that deals with matter,energy and their
interactions.
Physics
2. What is motion ?
Any body which is moving or is not at rest is known as
the body is in motion...
The basic knowledge of
physics starts up with
Motion.......
3. Types of motion...
• Rectilinear motion: An object moving in straight line.
• Curvilinear motion: A body moving along a curved path.
• Rotatory motion: An object moving around a fixed point.
• Oscillatory motion: The to and fro motion of an object like
pendulum of the clock.
• Vibratory motion: The motion of the sitar string when plucked
exhibits vibratory motion.
• Multiple motion: When an object possesses two or more type of
motion at same time.
4. Let us start up with some important
S.I units of the terms used in motion
at the level of 9th grade...
•What is S.I unit ? S.I unit refers to the
international system unit..
• Speed: meter per seconds.
• Velocity: meter per second.
• Acceleration: meter per second square.
• Distance: kilometer per hour.
5. There are some simple terms of physics
which are important to be told.......
• Distance: The proper length of path covered by an object with respect to time
is known as distance.
• Displacement: The shortest length of path between initial and final position is
known as displacement.
• Speed: Distance
Time
• Velocity: The rate of change of displacement is known as velocity.
• Acceleration: The uniform rate of increasing speed of the body
is known as acceleration ( it can be zero or positive and
negative ).
• Retardation: Negative acceleration by an body refers to the
body at retardation mode.
6. • Reference point: The location of an object is described by specifying its
reference point. The point from which location is observed and measured is
called the reference point. The reference point is also known as origin.
• Rest: If an object does not changes it's position with respect to time and the
fixed reference point or origin taken by us it is called as the body is at Rest.
• Uniform speed: When an object covers equal distance in equal interval of
time the speed of the body is known meant as uniform speed.
• Non-uniform speed: When an object does not covers equal distance in equal
interval of time the speed of the body is known as non-uniform speed.
• Scalar quantity: A physical quantity which is described completely by its
magnitude is called as Scalar quantity.
• Vector quantity: A physical quantity which is described completely by its
magnitude as well as with direction is called as vector quantity.
8. Their are three important
equations of motion...
• v= u + at. ( here v represents final velocity, u
initial velocity,a acceleration and t time.
• s= ut + 1/2 at
2
( here s represents displacement
but it is equal to distance in 2d )
• V + u = 2as22
9. In recent slide we read about the three different types of
equation of motion......now let us solve some questions
based on these equation of motion......
• Calculate the height of the body when it takes 4 seconds to reach
at top ?
• Ans. we have t = 4.
• We have third equation of motion. S = ut + 1/2 at
• S = 0*4 +1/2* 9.8*16
• S = 0 + 4.9*16
• S = 78.4
• The height attained by the body is 78.4 m.
2
( 9.8 m/s is the fore of gravity
of the earth )
10. Calculate the velocity of the body when it is
thrown vertically in upward direction and takes 2
sec to reach at top?
• We have 1st equation v= u + at.
• v = 0 + 9.8*2
• v = 19.6
• Final velocity is 19.6 m.
11. We solve some questions based
on these equations of motion...
Now let us learn about some facts based on
motion...
• Generally there is always zero
displacement of the body
moving on circular track
• The diameter of the circle is the displacement
of the body traveling around it.