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84 lessons · 1st Grade
Wind is moving air that pushes things. Sails catch wind to move boats!
Simple machines make work easier. A ramp helps you move heavy things to a higher place.
Magnets have a north pole and a south pole. Opposite poles attract, same poles push apart.
Wheels reduce friction and make it easier to move heavy objects.
Gravity is a force that pulls everything toward the ground. It is why you come back down when you jump!
Speed is how fast something moves. A cheetah is fast, a turtle is slow.
Friction is the force that slows things down. Rough surfaces have more friction than smooth ones.
A force is a push or a pull that can make things move, stop, or change direction.
Magnets are used in many things: fridge doors, compasses, and even some toys.
The stronger the push or pull, the more an object moves. A hard kick sends a ball farther!
A pulley is a wheel with a rope. It helps you lift heavy things by changing the direction of your pull.
A balance scale compares the weight of two objects. The heavier side goes down!
Energy makes things happen. Moving things have kinetic energy. A ball at the top of a hill has potential energy.
Objects in motion tend to keep moving. Objects at rest tend to stay still. Push something to start it!
Things roll, slide, bounce, or spin depending on their shape and the forces acting on them.
When you throw a ball up, gravity pulls it back down. The harder you throw, the higher it goes!
An inclined plane is a flat surface that is tilted. Ramps and slides are inclined planes!
A magnet can push or pull another magnet without touching it. That is amazing!
A lever is a simple machine. A seesaw is a lever—push down on one end and the other goes up!
Springs store energy when you squish or stretch them. When you let go, they bounce back!
Static electricity can make your hair stand up! Rub a balloon on your head and see!
Gravity is the same force that keeps the moon going around the Earth!
Air resistance slows things down as they move through the air. A parachute uses air resistance!
When two surfaces rub together, friction produces heat. Rub your hands together to feel it!
Friction helps you walk. Without friction, your feet would slip on the floor!
A wedge is a simple machine shaped like a triangle. A doorstop is a wedge!
A top spins because you give it a twist. It slows down because of friction with the air and surface.
Brakes on a bike use friction to slow down and stop. Press the brakes and friction does the work!
Sound is caused by vibrations. When you pluck a guitar string, it vibrates and makes sound!
A pendulum swings back and forth using the forces of gravity and momentum.
