What is Speed and Velocity?
Although speed and velocity are more often used interchangeably in everyday life, they represent different quantities in physics.
What is Speed?
Velocity is a measure of how fast an object is moving relative to a reference point. It has no direction and is considered a scalar quantity or quantity. Speed can be calculated by the formula:
Speed = Distance/Time
or
s = d/t
How to Measure Speed
In the United States, we mainly think of speed in miles per hour or mph. This is how the speed of a car is usually measured. In science and physics, the standard unit for measuring speed is usually meters per second or m/s.
The speed measurement can reflect two different scalar quantities.
Instantaneous Speed – The speed of an object at a given time. The car may be traveling at 50 mph right now, but it could slow down or accelerate in the next hour.
Average Speed – Average speed is calculated as the distance traveled by an object in a given period of time. If a car has traveled 50 miles in one hour, its average speed will be 50 miles per hour. The vehicle may have traveled at instantaneous speeds of 40 mph and 60 mph during this time, but the average speed was 50 mph.
What is Velocity?
Velocity is the rate at which an object changes position. Velocity has magnitude (velocity) and direction. Velocity is a vector quantity. Velocity is expressed by the formula:
Velocity = the change in distance/change in time
Velocity = Δx/Δt
How to Measure Velocity
Velocity has the same unit of measure as velocity. The standard unit of measurement is meters per second or m/s.
What is the difference between Speed and Velocity?
Velocity is the magnitude of velocity. Velocity is the speed of an object plus its direction. Velocity is called a scalar quantity and velocity is a vector quantity.
Speed of Light
The fastest possible speed in the universe is the speed of light. The speed of light is 299,792,458 meters per second. In physics, this number is represented by the letter “c”.
Interesting Facts about Speed and Velocity
Galileo was the first scientist to measure speed by distance over time.
Speedometers are a great example of instantaneous speed.
The speed of light can also be written as 186.282 miles per second.
The speed of sound in dry air is 343.2 meters per second.