How does gravity affect an object's velocity?

Gravity affects an object's velocity by constantly accelerating it towards the centre of the gravitational source.

Gravity is a force that pulls objects towards each other. The most familiar example of this is the pull of the Earth's gravity on objects on its surface. This force of gravity results in an acceleration, which changes the velocity of the object. This is why, when you drop something, it starts off stationary and then speeds up as it falls - its velocity is increasing because of the acceleration due to gravity.

The acceleration due to gravity on Earth is approximately 9.8 metres per second squared. This means that for every second an object is falling, its velocity increases by 9.8 metres per second. So, after one second, its velocity would be 9.8 m/s, after two seconds, 19.6 m/s, and so on. This is assuming no other forces are acting on the object, like air resistance.

Gravity doesn't just affect objects on the Earth's surface. It also affects objects in space. For example, the Moon is constantly falling towards the Earth due to gravity, but it's also moving sideways fast enough that it keeps missing! This is what an orbit is - a balance between the forward motion of the object and the pull of gravity.

In summary, gravity affects an object's velocity by causing it to accelerate towards the source of the gravitational force. This can result in an object falling to the ground, or in an object orbiting a planet. Understanding how gravity affects velocity is fundamental to understanding motion under gravity, whether that's an apple falling from a tree or a satellite orbiting the Earth.