Physics
Answer
The difference between speed and velocity is as follows:
| Speed | Velocity |
|---|---|
| The distance travelled per second by a moving object is called its speed. | The distance travelled per second by a moving object in a particular direction is called its velocity. |
| It is a scalar quantity. The speed does not tell us the direction of motion. | It is a vector quantity. The velocity tells us the speed as well as the direction of motion. |
| The speed is always positive since direction is not taken into consideration. | The velocity can be positive or negative depending upon the direction of motion. |
| After one round in a circular path, the average speed is not zero. | After completing each round in a circular path, the average velocity is zero. |
Related Questions
A body moving with a constant acceleration travels the distances 3 m and 8 m respectively in 1 s and 2 s.
Calculate —
(i) the initial velocity, and
(ii) the acceleration of body.
A car travels with a uniform velocity of 25 m s-1 for 5 s. The brakes are then applied and the car is uniformly retarded and comes to rest in further 10 s.
Find —
(i) the distance which the car travels before the brakes are applied,
(ii) the retardation and
(iii) the distance travelled by the car after applying the brakes.
A space craft flying in a straight course with a velocity of 75 km s-1 fires its rocket motors for 6.0 s. At the end of this time, its speed is 120 km s-1 in the same direction.
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(ii) the distance travelled by the space craft in the first 10 s after the rocket motors were started, the motors having been in action for only 6.0 s.
A train starts from rest and accelerates uniformly at a rate of 2 m s-2 for 10 s. It then maintains a constant speed for 200 s. The brakes are then applied and the train is uniformly retarded and comes to rest in 50 s.
Find —
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(ii) the retardation in the last 50 s,
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