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High School Physical ScienceUnit 10SPS8.d

Simple Machines

Machines trade force for distance. They never, ever reduce the work.

The piano problem.

A moving crew has to get a 2,500 N piano into a truck bed 1 m off the ground. Nobody can lift it. So they lay down a long ramp, and ONE mover pushes it up with about 250 N — roughly the effort of pushing a loaded shopping cart uphill. That's one-tenth of the force! Where did the "missing" force go — and what did the mover have to give up?

Start: What Do You Already Know? → Explore on your own ↓
7activities
14new words
3parts
∞replays — new every time
Open world

Explore

Jump in anywhere, in any order. Every activity reshuffles each time you play, so there's always something new. You earn joules for every right answer.

Think about it

Big questions to wonder about

By the end of this unit, you'll be able to answer every one of these.

How can a ramp make a 2,500 N piano feel like 250 N — without breaking the laws of physics?

You push on a wall until you're exhausted. Did you do any work?

Why does a flagpole pulley make you pull DOWN to raise the flag UP?

How many simple machines are hiding in a bicycle?

Vocabulary

Word Wall

The 14 words you'll own by the end of this unit. Tap any card to flip it. Words you collect in the activities get a ✓.

The road ahead

Unit Roadmap

Three parts, in the order we'll learn them.

1

Part 1: Work & Power

  • What counts as work
  • The three-part work test
  • W = F × d
  • Power (P = W ÷ t)
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2

Part 2: The Six Simple Machines & Mechanical Advantage

  • What a machine does
  • Meet all six
  • MA two ways
  • Lever classes & pulleys
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3

Part 3: The Trade-Off & Compound Machines

  • The rule machines can't break
  • The ramp proof
  • Efficiency
  • Compound machines
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Where we're headed

Learning Targets & Success Criteria

Learning Targets

I am learning to…

  • Calculate work and power, and explain when work is (and isn't) being done
  • Identify the six simple machines and how each changes the size or direction of a force
  • Calculate mechanical advantage and efficiency
  • Explain why machines trade force for distance but never reduce the work
Success Criteria

I will be successful when I can…

  • Use W = F × d and the three-part work test to decide whether work is done
  • Name and spot all six simple machines in everyday objects
  • Calculate mechanical advantage two ways: output force ÷ input force, and input distance ÷ output distance
  • Sort levers into three classes and count the strands supporting a pulley load
  • Calculate efficiency and explain why it is always less than 100%
  • Break a compound machine (scissors, a bike) into its simple machines
Georgia Standards of Excellence

Standards

SPS8

Obtain, evaluate, and communicate information to explain the relationships among force, mass, and motion.

SPS8.d

Use mathematics and computational thinking to identify the relationships between work, mechanical advantage, and simple machines.

Watch

One-minute videos

Quick previews from Simple Science Videos.

Simple Machines

SPS8.d