Speed Formula Physics
The speed formula describes the rate at which an object travels a certain distance at a certain time. The speed formula is frequently used in problems about certain Physics topics, including travel in a straight line, circular motion, boats, competitions, clocks, and many more. Although the Speed formula is used in Questions based on Time and Distance which are very common and frequent in competitive exams. Let’s learn the speed Formula, its units, and its applications with some examples.
Speed Formula Maths
Have you ever seen the banners beside the highways while driving that ‘ Max Speed 40 km/h ‘? It means you should drive at the rate of 40 km per hour on the highway.
The definition of speed is the rate at which an object travels from one place to another over a set period of time. In other words, The distance that an object travels in a certain amount of time is a common way to measure speed. It is a scalar quantity since it simply describes the magnitude of an object’s motion, not its direction. A moving object’s speed can be determined using the formula:
Speed = Distance ÷ Time |
Speed Calculator: Units of Speed
If you give a look at the speed formula. we see that speed is determined by dividing the distance traveled by the object by the total time taken. The unit of speed is derived from units of distance and time. The SI unit of speed is the meter per second (m/s).
CGS system | cm.s^{-1} |
SI system | ms^{-1} |
The speed dimensional formula is [LT-1]. How quickly a body is travelling is measured by its speed. The most often used unit of speed in daily life is the kilometer per hour (km/h), or miles per hour (mph) in the US and the UK. . The knot is frequently utilized for maritime and air transport.
Formula for time
We can easily calculate the time that is taken by an object to cover a distance at a certain speed. Earlier we know that the speed formula is expressed as,
Speed = Distance/ Time
Or, Time = Distance / Speed
So, We can Calculate the Time taken by an object from the speed formula, by dividing the total Distance traveled by its speed.
Speed Formula: Types of Speed
There are four different types of speed as follows
- Uniform speed- When an object travels an identical distance in a same amount of time, this is referred to as having uniform speed.
- Variable speed- A moving object is considered to be moving at a variable speed when it travels a varying distance at regular intervals.
- Average speed- Average speed is the rate of speed over the course of a journey, and it is computed by dividing the entire distance traveled by the total time it took to cover that distance.
- Instantaneous speed- Instantaneous speed is the speed at a certain instant or the speed considered to be constant throughout a very shorter amount of time
Average Speed Formula
Average speed is calculated by dividing the total distance traveled by the time period. The unit of average speed in kilometers per hour (km/h), is calculated by dividing a distance in kilometers (km) by a time in hours (h). The average speed formula is as follows :
Average Speed= Total Distance / Traveled Total Time Taken
For instance, if a man 80 kilometers traveled in an hour, then his average speed is 80 kilometers per hour. The average speed is similarly 80 kilometers per hour if 320 kilometers are covered in 4 hours.
Average speed does not capture the differences in speed that might have occurred during shorter time periods (as it is the entire distance covered divided by the total time of travel),
Instantaneous Speed Formula
The speed of an object at a specific time is its instantaneous speed. The instantaneous velocity is obtained by adding the direction to the speed. Instantaneous speed is the speed at a certain instant or the speed considered to be constant throughout a very shorter amount of time. One can always read the current instantaneous speed of a moving object with a speedometer. A bike traveling at 40 km/h typically maintains its speed for less than an hour, but if it did so for the entire hour, it would cover 40 km. The car would travel half that distance in 30 minutes if it kept moving at that speed (20 km).
Instantaneous speed formula (v) = distance/ time
Speed Formula: Difference Between Velocity and Speed
While velocity describes both how fast and in which direction an object is traveling, speed merely indicates how rapidly an object is moving.
A car’s speed has been mentioned if it is stated to be 60 km/h. But now that the car’s speed has been stated, it is claimed to be traveling at 60 km/h to the north.
When considering motion in a circle, a significant difference can be seen. The average speed of an object traveling in a circle and returning to its starting point is equal to zero, but the average speed is calculated by dividing the circle’s radius by the time required to complete the circle.
Speed Formula with Acceleration
The rate at which an object’s velocity or change of Speed with respect to time changes is referred to as acceleration. It is a vector quantity to accelerate (in that they have magnitude and direction). The direction of the net force acting on an object determines the direction of its acceleration. Acceleration is measured in meters per second square (m/s²) in the SI system. The speed Formula with Acceleration is expressed as follows
Acceleration = Change in speed / Time Acceleration = (Final Speed – Initial speed) / Time |
Speed Formula: Solved Problems
Q. A car travels at a distance of 180km in 6 hours. Find the speed of the car.
Solution: A moving object’s speed can be determined using the formula
Speed = Distance ÷ Time
In the given problem, Distance = 180 km and Time taken = 6 hours.
Hence, the speed of the car is = 180km / 6 hours = 30 km/h.
Q.Rafiq cycled 10 km in 5 hours. reaches a distant station. Find out the speed of the bicycle.
Solution: Speed can be determined using the formula
Speed = Distance ÷ Time
In the given problem, Distance = 10 km and Time taken = 10 hours.
Hence, the speed of rafiq is = 10km / 5 hours = 2 km/h.
Speed Formula-FAQs
Q. What formula is used for speed?
A moving object’s speed can be determined using the formula, Speed = Distance ÷ Time