1. Introduction to Motion
Rest and Motion: Definitions with examples.
Types of Motion:
Translational (Rectilinear and Curvilinear)
Rotational
Oscillatory
2. Describing Motion
Distance and Displacement
Scalar vs Vector quantities
Differences and examples
3. Uniform and Non-uniform Motion
Uniform Motion: Constant speed in a straight line
Non-uniform Motion: Varying speed or direction
4. Speed and Velocity
Speed: Scalar quantity; distance/time
Velocity: Vector quantity; displacement/time
Types of Speed: Average speed, instantaneous speed
Difference between speed and velocity
5. Acceleration
Definition: Change of velocity per unit time
Formula:
𝑎
=
𝑣
−
𝑢
𝑡
a=
t
v−u
Positive and Negative Acceleration
Uniform and Non-uniform Acceleration
6. Graphical Representation of Motion
Distance-Time Graphs:
For uniform motion: straight line
For non-uniform motion: curved line
Velocity-Time Graphs:
Uniform acceleration: straight line
Non-uniform acceleration: curve
Calculating acceleration and distance using graphs
7. Equations of Motion (by Uniform Acceleration)
Three equations:
𝑣
=
𝑢
+
𝑎
𝑡
v=u+at
𝑠
=
𝑢
𝑡
+
1
2
𝑎
𝑡
2
s=ut+
2
1
at
2
𝑣
2
=
𝑢
2
+
2
𝑎
𝑠
v
2
=u
2
+2as
Where:
𝑢
u = initial velocity
𝑣
v = final velocity
𝑎
a = acceleration
𝑠
s = displacement
𝑡
t = time
8. Uniform Circular Motion
Motion along a circular path with constant speed
Centripetal force
Examples: satellite motion, stone tied to a string, etc.
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Welcome to the fascinating world of motion! Motion is everywhere around us - from the simple act of walking to the complex orbits of planets around the sun. Let's start by understanding what rest and motion really mean. An object is at rest when its position doesn't change with time relative to a reference point. Motion occurs when an object's position changes with time relative to a reference point. Watch as this car demonstrates motion while the tree remains at rest.
Now let's explore the three main types of motion. First is translational motion, which can be rectilinear - motion in a straight line like this red ball, or curvilinear - motion along a curved path like this blue ball. Second is rotational motion, where an object spins around an axis, like this wheel rotating. Third is oscillatory motion, which involves repetitive back and forth movement, like this pendulum swinging. Each type of motion has unique characteristics that help us understand how objects move in our world.
Now let's understand the difference between distance and displacement. Distance is a scalar quantity that represents the total path length traveled, regardless of direction. It only has magnitude and is always positive. Displacement, on the other hand, is a vector quantity that represents the shortest straight-line path from the starting point to the ending point. It has both magnitude and direction. Watch this example: if an object travels along this blue path, the total distance is 6 meters, but the displacement is only 4.5 meters in the northeast direction. This demonstrates why scalars have only magnitude while vectors have both magnitude and direction.
Speed and velocity are fundamental concepts in motion. Speed is a scalar quantity calculated as distance divided by time, having only magnitude. Velocity is a vector quantity calculated as displacement divided by time, having both magnitude and direction. This graph shows uniform motion with constant speed as a straight line, and non-uniform motion with varying speed as a curved line. We distinguish between average speed over a time interval and instantaneous speed at a specific moment. While speed is always positive or zero, velocity can be negative when motion is in the opposite direction. Watch how the speedometer shows changing speed as our object moves.
Acceleration is the rate of change of velocity with time. The basic formula is a equals v minus u over t, where v is final velocity, u is initial velocity, and t is time. From this, we derive three key equations of motion for uniform acceleration. First: v equals u plus at. Second: s equals ut plus half at squared. Third: v squared equals u squared plus 2as. These equations help us solve motion problems when acceleration is constant. The velocity-time graph shows uniform acceleration as a straight line and non-uniform acceleration as a curve. Watch how the car accelerates, demonstrating increasing velocity over time according to our equations.