Vocabulary

energy - the ability to do work

input - the energy that goes into a system

converter - the part of the system that changes the energy

output - the energy that comes out after the transformation.

potential energy - stored energy

kinetic energy - energy of motion

Have you ever watched a luge team get ready to do their run on the track? At the top, the team will rock back and forth before running for a short distance and then jumping into the sled. With no engine, there is no propulsion, which is why the team doesn't simply jump in the sled to go down the hill. The object of this sport is to get to the bottom of the hill safely and with the fastest time. 

At the top of the run, the energy of the luge and the rider is called potential energy (stored energy). As soon as the team begins their run, their gravitational potential energy is converted into kinetic energy (energy of motion). 

We will be looking at the relationship between potential energy and kinetic energy.

What is a Pendulum? 

A pendulum is a weight that swings back and forth due to gravity.

Energy Transformations in a Pendulum:

• At the highest point: Maximum gravitational potential energy, no kinetic

• At the lowest point: Maximum kinetic energy, minimal potential

• Energy transforms back and forth between potential and kinetic as it swings

Parts of an Energy System

Input - Energy from lifting or pulling a bob

Converter - Gravity (causes the swing)

Output - Kinetic energy (movement)

Newton's Laws of Motion

⚖️ Newton’s First Law: The Law of Inertia

An object at rest stays at rest, and an object in motion stays in motion at a constant speed and in a straight line unless acted upon by an unbalanced force.

Example: A hockey puck will keep sliding on ice until friction or a player stops it.

Key idea: Things keep doing what they’re doing unless something changes it.

🏋️‍♂️ Newton’s Second Law: Force = Mass × Acceleration (F = ma)

The acceleration of an object depends on the mass of the object and the force applied to it.

Example: It’s harder to push a heavy box than a light one.

If you apply more force, it speeds up more

Formula: F = m × a

(Force in newtons = mass in kg × acceleration in m/s²)

🔁 Newton’s Third Law: Action and Reaction

For every action, there is an equal and opposite reaction.

Example: When you jump off a boat, the boat moves backward.

Rockets launch because gases push down and the rocket moves up.