速度是每单位时间的行进距离。它是物体移动的速度。速度是标量，即速度矢量的大小。它没有方向。更高的速度意味着物体移动得更快。较低的速度意味着它移动得更慢。如果它根本不移动，它的速度为零。该等式给出了物体在一段时间内的平均速度。在时间间隔期间，对象可能在不同点上变得更快或更慢，但我们在这里看到它的平均速度。当时间间隔接近零时，瞬时速度是平均速度的极限。当你看车内的速度表时，你会看到瞬时速度。虽然你可能已经每小时跑60英里，但10分钟的平均速度可能远远低于或远低于此。速度是一个标量，它不考虑方向，而速度是一个知道方向的矢量。如果跑过房间然后回到原来的位置，你会有一个速度 – 距离除以时间。但是你的速度将为零，因为你的位置在间隔的开始和结束之间没有变化。在这段时间结束时没有看到任何位移。如果在您从原始位置移动的位置拍摄，则会有瞬时速度。如果向前走两步，后退一步，你的速度不会受到影响，但你的速度会受到影响。转速或角速度是在圆形路径中行进的物体在一个单位时间内的转数。每分钟转数（rpm）是一个常见的单位。但是当物体旋转时，物体与轴的距离（其径向距离）决定了它的切向速度，即圆形路径上物体的线速度。在一个rpm时，位于记录盘边缘的点在一秒内覆盖的距离比靠近中心的点多。在中心，切向速度为零。切向速度与径向距离乘以旋转速度成正比。切向速度=径向距离x转速。
新加坡国立大学物理学Assignment代写:物理学中速度的定义
Speed is the distance traveled per unit of time. It is how fast an object is moving. Speed is the scalar quantity that is the magnitude of the velocity vector. It doesn’t have a direction. A higher speed means an object is moving faster. A lower speed means it is moving slower. If it isn’t moving at all, it has zero speed. This equation gives the average speed of an object over an interval of time. The object may have been going faster or slower at different points during the time interval, but we see here its average speed. The instantaneous speed is the limit of the average speed as the time interval approaches zero. When you look at a speedometer in a car, you are seeing the instantaneous speed. While you may have been going 60 miles per hour for a moment, your average rate of speed for 10 minutes might be far more or far less. Speed is a scalar quantity, it does not account for direction, while velocity is a vector quantity which is aware of direction. If ran across the room and then returned to your original position, you would have a speed – the distance divided by the time. But your velocity would be zero since your position didn’t change between the beginning and the end of the interval. There was no displacement seen at the end of the time period. You would have an instantaneous velocity if it were taken at a point where you had moved from your original position. If you go two steps forward and one step back, your speed isn’t affected, but your velocity would be. Rotational speed or angular speed is the number of revolutions over a unit of time for an object traveling in a circular path. Revolutions per minute (rpm) is a common unit. But how far from the axis an object is (its radial distance) as it revolves determines its tangential speed, which is the linear speed of an object on a circular path. At one rpm, a point that is at the edge of a record disk is covering more distance in a second than a point closer to the center. At the center, the tangential speed is zero. Your tangential speed is proportional to the radial distance times the rate of rotation. Tangential speed = radial distance x rotational speed.