Earth & Space
Levers, pulleys and gears — simple mechanisms that turn a small force into a much bigger effect.
⏱ Whole lesson ≈ 44 min · pick a tier in the bar, or leave on "All"
Recap of last lesson: gravity, mass and weight.
Gravity is a ____ force that pulls objects ____.
Some jobs need a big force. How might a simple machine let a small force do a big job?
Try to open a tin lid with fingers, then with a lever (spoon).
A mechanism changes a small force into a larger one, making jobs easier. Three key ones: levers, pulleys and gears.
Match: seesaw → ? bicycle → ? flagpole rope → ?
Give a real example of a lever, a pulley and a gear.
Why does using a lever let you lift something you couldn't lift by hand?
Teacher models. Watch, then name the three mechanisms.
Swap the clip: change the ID after /embed/ (now Kc_q6AH_CWY).
Match everyday objects to the mechanism they use.
🪚 seesaw 🚲 bicycle gears 🚩 flagpole rope ✂️ scissors 🏗️ crane
Play the animation. Bust: bigger gear / longer lever means faster or easier is not always so.
A small effort far from the pivot lifts a big load close to it.
Watch for: "bigger gears spin faster" — it's the smaller gear with fewer teeth that spins faster.
Sort a few examples as a class.
On your own. Sort each example, then write at your tier.
Tap a card to sort it…
Sort the cards. Then finish: A mechanism turns a small force into a ____ one.
Sort them, then write how a lever makes lifting a heavy load easier.
Explain why smaller gears spin faster, and why moving effort further from the pivot helps.
Answer at your tier, then hand it in. Block review.
Pick one mechanism and explain how it lets a smaller force have a greater effect.