When we drop an object, it zooms towards the Earth due to gravity. The earth pulls the object down, and fun fact - the object also pulls Earth upwards! But don't worry, you won't feel the Earth move under a falling apple because Earth is so massive compared to the apple.

Gravity's strength varies around the globe! Imagine you're in Kuala Lumpur - there gravity's strength (acceleration due to gravity or 'g') is 9.776 \(\frac {m}{s^2}.\) Now, hop on a plane to Stockholm - there, it's 9.818 \(\frac {m}{s^2}.\). This difference is because Earth is more like a squished orange than a perfect sphere and the rocks under our feet change in density from place to place.

A fun little quirk of gravity is that if you're buying gold, do it at the equator and sell it at the North Pole. You'd make a tiny profit thanks to the difference in 'g'. But remember, this only works when buying by weight, not mass!

The kinematic equations are our best friends in physics. They're like a simple model or a blueprint that describes how things move under uniform acceleration. But they do have some rules - one of them is that they see all objects as point masses. That's like imagining every object is just a tiny dot!

You'll also come across the centre of mass concept, which is the average position of all the particles in an object. It’s like the balancing point of an object.

The kinematic equations are great, but they can't handle changing acceleration. If an object starts speeding up or slowing down differently, the kinematic model breaks down. Enter stage - Newton's second law of motion! This law links forces to acceleration and will be our saviour when dealing with changing accelerations.