Example
Difference between uniform and non-uniform motion
| Uniform Motion | Non-Uniform Motion |
| When an object travels equal distance in equal interval of time . | When an object travels unequal distance in equal interval of time. |
| For example : If a car covers equal distance of 500m in the interval of 2 minutes. | For example : Motion of car on a crowded road when it covers unequal distance in equal interval of time. |
Definition
Non-uniform Motion
A body is said to have non-uniform motion if its velocity changes with time. Such a body is necessarily under the influence of an external force. An example of non-uniform motion is a body rotating at a constant speed. Its velocity is not constant because its direction of motion changes every instant.
Definition
Uniform v/s Non-uniform motion
| S.No. | Uniform Motion | Non-Uniform motion |
| 1. | Velocity is constant with time. | Velocity changes atleast once in the given interval of time. |
| 2. | External force is zero. | External force is non-zero. |
| 3. | Ideal scenario. | Realistic scenario. |
| 4. | Ex: Body moving on a frictionless table | Ex: Body under freefall |
Definition
Velocity
Velocity is defined as the rate of change of displacement with time.
It is a vector quantity and has units m/s.
The direction of a velocity vector is same as the direction of the motion of body at that instant of time. Magnitude of instantaneous velocity is same as the speed at the instant.
It is a vector quantity and has units m/s.
The direction of a velocity vector is same as the direction of the motion of body at that instant of time. Magnitude of instantaneous velocity is same as the speed at the instant.
Definition
Uniform motion
A body is said to be in uniform motion if it moves with a constant velocity. If the magnitude and/or direction of the velocity changes, then the body is not in uniform motion.
Note:
If a body is in uniform motion, then the net external force on the body is zero. Inverse of the statement is also true (If the net external force on the body is zero, then the body is in uniform motion).
Note:
If a body is in uniform motion, then the net external force on the body is zero. Inverse of the statement is also true (If the net external force on the body is zero, then the body is in uniform motion).
Definition
Average speed
Average speed is defined as the total distance travelled by the body in total time i.e.
It is a scalar quantity. Its unit is m/s.
It is a scalar quantity. Its unit is m/s.
Definition
Calculating average speed
Average speed is found by first finding the total distance covered by the object and dividing it by the total time taken in travelling the distance.
Example:
A boy covers a circle of radius m in s.
The total distance covered by him will be
Average speed will be
Example:
A boy covers a circle of radius m in s.
The total distance covered by him will be
Average speed will be
Definition
Average velocity
It is a vector quantity and has units of m/s.
Magnitude of average velocity is always less than or equal to the average speed because displacement is always smaller than or equal to distance.
Definition
Non-Uniform Speed and Velocity
Non-Uniform Speed : When a body covers unequal distances in equal intervals of time, then that body is said to be in non uniform speed.
For e.g., an object thrown into air, like stone, moves at non-uniform speed, lift used to go up or down in a building.
Non-Uniform Velocity : When the velocity is not uniform i.e. not constant. This implies that the velocity of the object moving with non uniform velocity is either increasing or decreasing with time i.e. the object is accelerating or decelerating.
Since velocity is a vector quantity, hence it depends on two factors namely speed and direction.
If any of the two will change, velocity will also get changed.
So, we can say that the object is moving with non uniform velocity, if an object is :
1. changing speed wrt time but in the same direction.
2. changing direction wrt time while moving with constant speed.( e.g., motion of a particle in a circular path with constant speed)
3. changing both speed and direction wrt time.
For e.g., an object thrown into air, like stone, moves at non-uniform speed, lift used to go up or down in a building.
Non-Uniform Velocity : When the velocity is not uniform i.e. not constant. This implies that the velocity of the object moving with non uniform velocity is either increasing or decreasing with time i.e. the object is accelerating or decelerating.
Since velocity is a vector quantity, hence it depends on two factors namely speed and direction.
If any of the two will change, velocity will also get changed.
So, we can say that the object is moving with non uniform velocity, if an object is :
1. changing speed wrt time but in the same direction.
2. changing direction wrt time while moving with constant speed.( e.g., motion of a particle in a circular path with constant speed)
3. changing both speed and direction wrt time.
Definition
Instantaneous speed
Instantaneous speed can be defined as the rate of change of distance with respect to time.
Note:
1. Instantaneous speed is always greater than or equal to zero and is a scalar quantity.
2. For uniform motion, instantaneous speed is constant.
Note:
1. Instantaneous speed is always greater than or equal to zero and is a scalar quantity.
2. For uniform motion, instantaneous speed is constant.
 |
| BookMarks |
Page 11 Page 12 Page 13 Page 14
0 Comments
Post a Comment