This gives us an idea about the direction of the object. For example, let us imagine that a car travels at 20kmph. But if you know that the car is traveling at 20kmph to the North, then the physicist would say that the speed of the car is 20kmph and its velocity is 20kmph in the North direction. There is always a comparison drawn between speed and velocity regarding the motion of an object.
These two entities are constantly pitted against each other to see which is superior. But there is no point comparing vector and scalar quantities because they are distinct in their ways. To give a rough idea, consider an object traveling in a perfect circle at 20 kmph. Since this is a perfect circle and we have defined a constant rate of motion for it, speed and velocity should be the same, right?
In this case, the speed of the object is constant, but the velocity is always changing. This is because we consider direction when defining velocity. So when an object travels in a circle, we find that its direction is always in a state of change.
If we find out the direction of that object at any given point, it will be tangential to the outline edge of that circle. When we talk about the standard equation, almost always, we are talking about average speed and average velocity. However, sometimes it is necessary to know the velocity or speed at an instant. The velocity of an object at a specific point in time is known as instantaneous velocity.
The general equation for instantaneous velocity is:. The speed of an object at a specific point in time is known as instantaneous speed. The general equation for instantaneous speed is:. The most common example of the measurement of instantaneous speed is a speedometer. Speedometers show the speed of an object in a particular instant, not its average value. The task of describing the direction of the velocity vector is easy.
The direction of the velocity vector is simply the same as the direction that an object is moving. It would not matter whether the object is speeding up or slowing down. If an object is moving rightwards, then its velocity is described as being rightwards.
If an object is moving downwards, then its velocity is described as being downwards. Note that speed has no direction it is a scalar and the velocity at any instant is simply the speed value with a direction.
Let's begin implementing our understanding of these formulas with the following problem:. Q: While on vacation, Lisa Carr traveled a total distance of miles. Her trip took 8 hours. What was her average speed? That was easy! Lisa Carr averaged a speed of 55 miles per hour.
Yet, she averaged a speed of 55 miles per hour. The above formula represents a shortcut method of determining the average speed of an object. Since a moving object often changes its speed during its motion, it is common to distinguish between the average speed and the instantaneous speed.
The distinction is as follows. You might think of the instantaneous speed as the speed that the speedometer reads at any given instant in time and the average speed as the average of all the speedometer readings during the course of the trip. Moving objects don't always travel with erratic and changing speeds.
Occasionally, an object will move at a steady rate with a constant speed. That is, the object will cover the same distance every regular interval of time. If her speed is constant, then the distance traveled every second is the same. The runner would cover a distance of 6 meters every second.
If we could measure her position distance from an arbitrary starting point each second, then we would note that the position would be changing by 6 meters each second. This would be in stark contrast to an object that is changing its speed.
An object with a changing speed would be moving a different distance each second. The data tables below depict objects with constant and changing speed. In the end, this is major difference between Speed and Velocity. By definition, the speed of an object is the magnitude of its velocity, or the rate of change of its position.
The average speed of an object in an interval of time is the distance traveled by the object divided by the duration of the interval. The fastest possible speed at which energy or information can travel, according to special relativity, is the speed of light in vacuum a. Velocity, on the other hand, is the measurement of the rate and direction of change in the position of an object.
0コメント