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Introduction |
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The branch of Physics, which deals with the behaviour of moving objects, is known as mechanics. Mechanics is further divided into two sections namely Kinematics and Dynamics. |
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Motion and Rest |
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Imagine yourself sitting in a seat while travelling in a moving train. You observe no change in position with respect to the window. There is change of scene when you view through the window. |
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Types of Motion |
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There are three types of motion: Translatory motion, Rotatory motion, Vibratory motion. |
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Distance and Displacement |
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Distance is a scalar quantity. SI unit of distance is metre.Displacement is the shortest distance covered by a moving object from the point of reference (initial position of the body), in a specified direction. |
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Uniform Motion and Non-uniform Motion |
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When a body covers equal distances in equal intervals of time then the body is said to describe uniform motion.When a body moves unequal distances in equal intervals of time or vice-versa, then the body is said to describe non-uniform motion. |
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Speed |
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Speed can be defined as the distance covered by a moving object in unit time. |
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Distance-Time Table and Distance-Time Graph |
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A distance-time graph is a line graph showing the variation of distance with time. |
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Distance-Time Graph for Uniform Motion |
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The distance-time graph is a straight line showing that the motion is uniform. |
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Distance-Time Graph for Non - Uniform Motion |
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Graphs can be easily read at a glance.Plotting graphs takes less time and is more convenient. |
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Velocity |
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Velocity is defined as the distance travelled in a specified direction in unit time. The distance travelled in a specified direction is displacement. |
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Acceleration |
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All of us know that a car moving on road does not have a uniform velocity. Either the speed or the direction changes. Whenever a vehicle is speeding i.e., when the speed is increased we say that the vehicle is accelerating. |
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Uniform Velocity and Non-uniform Velocity |
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Thus a body is said to be moving with uniform velocity if it covers equal distances in equal intervals of time in a specified direction.A body is said to be moving with variable velocity if it covers unequal distances in equal intervals of time and vice-versa in a specified direction or if it changes the direction of motion. |
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Circular Motion |
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An object moving along a circular track with uniform speed is an example for a non - uniform motion because the direction of motion of the object goes on changing at every instant of time. |
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Velocity-Time Graph |
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The variation of velocity with time can be represented graphically to calculate acceleration exactly like we calculated speed from distance-time graph. |
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v-t Graph |
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The acceleration produced in a body.The distance covered by a moving object.We can derive the equations of motion. |
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Speed - Time Graph |
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To calculate the distance covered by a moving object from speed-time graph. |
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Equations of Motion |
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The variable quantities in a uniformly accelerated rectilinear motion are time, speed, distance covered and acceleration. Simple relations exist between these quantities. |
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Summary |
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When a body covers equal distances in equal intervals of time then the body is said to describe uniform motion. |
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Question and Answers |
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Multiple Choice Questions |
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