Simple Machines
1. Lever
A lever is a simple machine that helps us lift or move objects by applying force. It has a fulcrum, a load, and an effort. The fulcrum is the point where the lever pivots, the load is the object you want to move, and the effort is the force you apply.
Imagine a seesaw in a playground. The middle part where it balances is the fulcrum, the kids sitting on either end are the load, and the force they use to push off the ground is the effort.
2. Wheel and Axle
A wheel and axle is a simple machine that helps us move things more easily. The wheel is the round part that turns, and the axle is the rod that goes through the center of the wheel. When you turn the wheel, the axle helps move the object.
Think of a toy car. The wheels are the round parts that spin, and the axles are the rods inside the wheels that help the car move forward when you push it.
3. Pulley
A pulley is a simple machine that helps us lift heavy objects by changing the direction of the force. It has a wheel with a groove in it and a rope or cable that runs through the groove. When you pull the rope, the pulley helps lift the object.
Imagine a flagpole. The flag is the object you want to lift, the rope is the part you pull, and the pulley at the top of the pole helps lift the flag by changing the direction of the force.
4. Inclined Plane
An inclined plane is a simple machine that helps us move objects up or down a slope. It reduces the effort needed to lift something by spreading the work over a longer distance. Examples include ramps and stairs.
Think of a slide at the playground. The slide is the inclined plane, and instead of lifting yourself up to the top, you walk up the stairs (the effort) and then slide down (the load).
5. Wedge
A wedge is a simple machine that helps us split or hold things together. It is made of two inclined planes joined together. Wedges are used to split wood, hold doors open, or even as knives.
Imagine a doorstop. The doorstop is the wedge, and it helps hold the door open by using the inclined planes to push against the floor and the door.
6. Screw
A screw is a simple machine that helps us hold things together or lift objects. It is an inclined plane wrapped around a cylinder. When you turn the screw, it moves through the material, holding things in place or lifting objects.
Think of a jar lid. The screw threads on the jar lid help you tighten it by wrapping around the jar, just like an inclined plane wrapped around a cylinder.