In this video, we dive into forces and motion to understand how objects move and stop. A force is anything that can make an object start moving, change speed, stop, or even change shape. Forces can push, pull, or twist objects, and they’re essential for all movement!

We learn that forces are either balanced or unbalanced. If forces are balanced, like when a parked car has equal forces pushing up and down, the object stays still or moves at a constant speed. But when forces are unbalanced, an object will either speed up, slow down, or change direction. Think of a car: if you press the accelerator, you’re adding thrust force to move the car forward. As it speeds up, air resistance pushes back, and eventually, these forces balance out. At this point, the car stops accelerating and goes at a constant speed.

The video also explores what happens when we add friction or brakes, which create forces that can slow down or stop a vehicle by making the forces unbalanced again.

We then look at a parachutist to see how these forces work in the air. When they jump, they accelerate because their weight (gravity pulling them down) is greater than air resistance. Eventually, they reach a top speed called terminal velocity, where weight and air resistance balance out, allowing them to fall at a constant speed. When they deploy the parachute, air resistance increases and slows them down, making it safer to land.

This idea can be shown on a velocity-time graph, which shows how speed changes over time. For Key Stage 3, understanding these basics helps in seeing how forces affect everything from riding a bike to jumping from a plane!

Balanced forces – Velocity stays the same

In this video, Kaleigh introduces us to forces and explains what they are, showing how forces are pushes, pulls, or even twists applied to objects. For a force to happen, two objects must interact—like someone pushing a fridge or pulling a cart. There are two main types of forces: contact forces, where objects physically touch, like pushing, and non-contact forces, which work at a distance, like gravity or magnetism.

Kaleigh then dives into balanced and unbalanced forces. When forces are balanced, they cancel each other out, so there’s no change in movement. But with unbalanced forces, movement or acceleration happens! For example, if you’re sitting in a chair, you aren’t accelerating because the force of gravity pulling you down is balanced by the chair pushing back up. But when you push a heavy book across a table, it’s a bit different. First, you have to overcome friction to get the book moving. Once you push hard enough, it moves, meaning the forces are unbalanced. When you stop pushing, friction takes over, slowing the book down.

To demonstrate these ideas, Kaleigh uses a game called Net Force. It’s a tug-of-war game, where teams pull on a cart full of candy. If both teams pull with equal strength, the forces are balanced, and there’s no movement.

But if one side has more force, the cart moves in that direction—this shows unbalanced forces in action!

Kaleigh ends by inviting us to play the game, watch for any acceleration (which is a change in speed or direction), and experiment with different combinations of players to see how forces work. This lesson makes it clear: forces are all around us, affecting everything we do!