One of the questions that come to kids’ minds as their thinking skills develop is why objects fall to the ground. It was an idea pondered over by many, from philosophers to ordinary people for ages, until Isaac Newton figured it out. Gravity is the force that brings a ball back to the ground when tossed or makes you fall when you slip. It is also the force that keeps the Earth going around the Sun, the force responsible for the existence of stars and galaxies in the universe. This article presents everything about the gravitational force for kids to build up their understanding of how it works and what its effects are.
What Is Meant by Gravity?
To define gravity for kids, it can be explained as a force of attraction that all objects with mass have between each other. Every object that has mass has a force of gravity, which it exerts on every other object with a mass around it. The more mass an object has, the stronger its gravitational attraction force is. This means that objects like planets and stars have a powerful gravitational force around them. The gravitational force also depends on the proximity of the two objects. The closer they are, the stronger their gravitational force.
When you toss a ball into the air, the Earth’s gravity acts continuously on it to pull it back to the ground. Without gravity, the ball would continue to go higher and higher into space. Gravity is also responsible for keeping the Moon orbiting the Earth, and the same goes for the Earth and the Sun.
All objects under the influence of Earth’s gravity experience an acceleration towards the centre of the Earth called ‘acceleration due to gravity.’ Denoted as ‘g,’ the acceleration due to the gravity of the Earth is 9.807 meters per second squared (m/s²).
Who First Discovered Gravity?
There had been many attempts to explain the motion of falling objects on Earth and even the motion of planets around the Sun. Galileo performed his famous experiment with heavy balls from the Tower of Pisa to show that objects accelerate at the same rate towards the ground regardless of their weight. Johannes Kepler came up with his three laws of elliptical orbits even without an understanding of gravity.
The first person to explain it mathematically was Sir Isaac Newton. The story goes that Newton realized the connection between what keeps the Moon going around the Earth is the same as what made the apple fall on his head as he sat under the apple tree. He called this force of attraction ‘Gravity’. Newton explained that the force of gravity between two objects is directly proportional to their masses and inversely proportional to the square of the distance between them.
Why Is Gravity Important?
Gravity is important because nothing in this would exist without it! Gravity’s influence can be traced back to the creation of stars from dust clouds in the early universe. Gravitational attraction creates enough heat in gas clouds that lead to the formation of stars. Stars forge the elements that make up all matter in our bodies and all the materials we use in our everyday life. Therefore, we owe our existence to gravity.
Gravity is also what keeps Earth bound to the Sun. If gravity were to disappear, the Earth would fly off in a tangent to outer space and eventually kill all life forms on the planet. The telecommunications satellites we use for the internet and other purposes stay in space because of the application of the laws of gravity and orbital mechanics. The Earth’s gravity keeps them in orbit and allows us to stay connected across the globe.
What if Gravity Didn’t Exist on Earth?
Without gravity on Earth, we wouldn’t be able to go about our routine lives. Gravity enables us to walk on land and drink water. It is also helpful when we exercise as it creates the effect of ‘weight’ in our bodies. Gravity enables rivers to flow to the ocean and keeps the ocean’s water in the lowest parts of the Earth’s crust, so it doesn’t flood all land on the planet. Gravity is also responsible for keeping the layer of air and gasses we call the atmosphere ‘stuck’ to the surface so we can all breathe and life can flourish on the planet.
Earth’s gravity causes all the objects around us to stay in their place. Without gravitational force, everything would attract everything else and clump together. But since the Earth’s gravity is stronger, it keeps everything stuck to the ground.
More Facts About Gravity for Children
Here are some more gravity facts for kids:
- Newton’s theory of gravity holds good for low mass objects and explaining mechanics on the Earth. Albert Einstein also explained gravity in his General Theory of Relativity, where he says that the effect of gravity is due to the bending of space around heavy objects.
- Gravity creates the effect of weight for all objects on Earth. The weight is determined by the mass of the object multiplied by the acceleration due to gravity constant ‘g’, which is 9.8 m/s². The value of ‘g’ is different for different planets. So your weight would be different on different planets.
- Since gravity causes the same effect as acceleration, your weight can vary based on how fast you are going up or coming down. Rollercoasters are designed keeping this effect in mind. When going up the track, the “g-force” increase can be as high as 4 times the normal gravity. What it means is that if your weight is 50 kilos standing on the ground, it will momentarily increase to 200 kilos when your rollercoaster pulls you up the track at high speed at 4 g!
- The high and low tides in oceans are caused by the Sun and the Moon’s gravitational effects.
- The Sun’s gravity pulls the planets towards itself and the planets’ speed keeps them in orbit around the Sun. Similarly, spacecraft sent in outer space from Earth orbit Earth despite its gravitational pull because of the spacecraft’s speed.
Gravity is a force of attraction between all objects that have mass. It is responsible for keeping everything functioning properly on Earth and enabling the Earth to go around the Sun. It controls the tides, the motion of satellites in orbit and influences all our daily activities.