keke
3 Answers
leeroy
Speed and velocity
Speed is how fast an object is going with respect to an object. Velocity is a measure of the speed in a given direction. You can say the top speed of an airplane is 300 kilometers per hour (kph). But its velocity is 300 kph in a northeast direction.
We distinguish between speed and velocity because if you add the speeds of objects, their directions are important. For example, the velocity of an airplane with respect to the ground would vary according to the direction of the wind.
Acceleration
Acceleration is the increase of velocity over a period of time. Deceleration is the decrease of velocity. When you start running, you accelerate (increase your velocity) until you reach a constant speed.
Mathematically, acceleration is the change in velocity divided by the time for the change
a = (v2 ? v1)/(t2 ? t1)
where:
* v2 ? v1 is the end velocity minus the beginning velocity
* t2 ? t1 is the measured time period between the two velocities
Often this is written as a = ?v/?t, where ? is the Greek letter delta and stands for difference.
For example, if an object speeds up from a velocity of 240 meters/second to 560 meters/second in a time period of 10 seconds, the acceleration is (560 - 240)/10 = 320/10 = 32 m/s/s or 32 m/s?.
Changing direction can also cause acceleration (or deceleration) because the velocity in that direction has changed.
Summary
Motion is change in position. All motion is relative to some fixed point or object. Speed is a measurement of that change in position over time. Velocity is speed in a given direction. Acceleration is the increase in speed or velocity over a period of time. Deceleration is the decrease of speed or velocity over time.
| 13 years ago. Rating: 2 | |
zenius
Speed is the rate of change of distance.
i.e Speed = total distance traveled / total time taken
Similarly , velocity is the rate of change of displacement.
i.e. Velocity = Total displacement / total time taken
and Acceleration is the rate of change of velocity.
i.e Acceleration = Change in velocity / time taken
The simple relation establishing speed or velocity and acceleration is:
v = u + at, where, v = final velocity of the body
u = initial velocity of the body
a = uniform acceleration of the body
and t = time taken by the body
This equation is valid only for uniform acceleration and also known as the First Equation of Motion.
Hope this has helped you to understand the relation between speed, velocity and acceleration.
Note: Speed and velocity are used in same sense, only the different in them is that velocity is related with direction and speed is not.
| 13 years ago. Rating: 1 | |
ady
