Scientifically speed of an object can be defined as the magnitude of its velocity. If we have to put this in simple terms then speed is the rate at which an object moves and covers a distance. The speed of an object may vary at different point of travel. In this case average speed is calculated by dividing total distance covered the time taken to cover the distance.
Fact 1: Highest speed is possessed by light. Everything else is measured in reference to its speed. It has speed of 299,792,458 meters per second which is 186,282 miles per second. It takes the sunlight, 8 minutes to reach the Earth. A light year is the distance travelled by light in a year and to cross the width of our galaxy, it takes 100,000 years with this speed.
Fact 2: When an object moves with certain speed it creates a force around it and due to this force, matter around the object gets attracted to it. The intensity of the force created around the object due to such movement depends on the speed and mass of the object and the force created this way is called ‘Gravity’.
Fact 3: Usually Speed and Velocity is used interchangeably. Velocity is the rate at which an object changes its position. In a way velocity is the speed of an object plus its direction. Velocity is measured using same units as the speed.
Fact 4: Escape Velocity of an object is the minimum speed required to escape from the gravity of that particular object. Escape velocity of Earth is 25,000 mph. This is the speed required to escape from the gravity of Earth while travelling in a straight direction away from the Earth surface.
Fact 5: Instantaneous speed is the speed of an object at a given time, for example the speed shown on the speedometer of a vehicle. But in general when we refer to speed, the speed is the average speed that is total distance covered divided by the time taken to cover the distance.
Fact 6: If we go on a drive in a car with a constant speed of 70mph, we can reach the moon in 5 months, the sun in 150 years, the Neptune in 4500 years and the nearest star in 40 million years. Of course it is impossible to go there with the car. But this was just to give an idea of the distance.
Fact 7: Usain Bolt is the fastest runner of all time right now with the speed 27.44 mph. However, in 2003 archaeologists found a 20,000 years old footprint in Australia which determined that there was man who ran at a speed of 23 mph. Scientist have a thought that if the man would exist today, he could probably beat Usain with the spiked and advanced shoes and a smooth, engineered track. It is just a thought.
Fact 8: First scientist to measure speed as distance over time was Galileo.
Fact 9: When an objects falls freely from up towards the ground, after a specific point the speed evens out. This speed of that object is known as its terminal velocity. For an average human body it is about 125mph. In normal atmospheric pressure it takes 14 seconds to reach this speed. But as the atmosphere gets less dense this time can be lesser.
Fact 10: The fastest animal on the land is the Cheetah with a speed of 64mph. Under water, the Atlantic sailfish is the one who is fastest with the speed of 68mph and in air it is Peregrine falcons, these can reach up to a speed of 200 mph in a dive.