Energy Never Dies

Why it matters

Drop a ball: height becomes speed. It bounces: speed becomes height again. Somewhere in the universe's ledger, the total never changed — it never does.

The idea in plain words

The conservation law. Tap the clauses.

energy is never created or destroyed

A ball dropped from 10 m arrives at the ground with how much of its PE as KE (no air resistance)?

All of it — 100% PE became KE

• allowed: conversion — energy changes form freely: PE↔KE, chemical→electrical→light…
• the law: conservation — the TOTAL in a closed system is fixed — physics' strictest accountant
• examples: transformations — torch: chemical→electrical→light · fan: electrical→kinetic · photosynthesis: light→chemical
• Nothing else took a share

Predict first

A swinging pendulum at its LOWEST point has…

All the height-energy has just been converted to speed — the bottom is the fastest, emptiest-pockets moment of the swing.

• maximum kinetic energy, minimum potential — correct
• maximum potential energy
• no energy — it's at the bottom

What you do

Drag the bob along its arc: watch PE pour into KE and back, while the total refuses to move.

Check yourself

In a torch, the energy chain is…

The battery's chemistry funds everything — the bulb just changes the currency twice.

Energy and power are different: power is…

Energy is the amount (J); power is the rate (W). A small motor can do the same WORK as a big one — it just takes longer.

Green plants convert…

Photosynthesis banks sunlight into sugar — the deposit every food chain lives on.

• chemical → electrical → light (+ heat) — correct
• light → chemical → electrical
• electrical only
• how FAST energy is used or converted (joules per second = watts) — correct
• just another word for energy
• measured in joules
• light energy into chemical energy (food) — correct
• chemical into light
• heat into oxygen