Velocity describes the speed and direction of an object. Speed tells how fast an object moves, but velocity is a vector measurement and includes both the rate and direction of an object's change of position.
Know MoreThe formula for calculating speed is distance traveled divided by time traveled. The formula for calculating velocity is the change of position, or displacement, divided by time. The difference between velocity and speed is more easily understood with the following example: a car completing a 10-mile course in 30 minutes has a speed of 20 miles per hour. If that car traveled at a speed of 20 miles per hour for five miles forward and then at the same speed for five miles in reverse, the velocity is zero because the car had no net displacement. It ended up in the same place it started.
Learn more about Motion & MechanicsMass does not affect speed directly, but it does affect how fast an object can change its speed by accelerating or decelerating. Objects with larger masses require more time for acceleration or deceleration compared to lighter objects.
Full Answer >The speed of an object is equal to the distance it travels divided by the amount of time it takes to travel the distance. This actually measures the average speed; instantaneous speed is the speed of an object at a given instant (as the time period approaches zero).
Full Answer >An object does not have a varying speed if its velocity is constant. A constant velocity implies that an object is moving in a straight line at an identical rate over time.
Full Answer >It is possible for an object to be accelerating if it has a zero speed or zero velocity. In such a case, the object only has zero speed for an instant.
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