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Builder's Lab / Week 11 / Tuesday
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Week 11 · Lift It

Tuesday

Levers and pulleys
// A lever or pulley that lifts a small load
⏱ about 20 min

Tuesday: Levers and Pulleys

Raven lays a ruler across a round marker, like a seesaw.

Rocket presses one end. The other end pops up!

Then Raven loops a string over a thread spool on a pencil.

She pulls down. The cup on the other end goes up!

Nova sparkles. "Two machines! What do you notice?"

The lever

A lever is a stiff bar that turns on a point.

The point is called the fulcrum.

Put the load close to the fulcrum.

Then it takes less effort to lift it.

The pulley

A pulley is a wheel with a string around it.

You pull down on one side. The load goes up.

A simple pulley changes the direction of your pull.

It does not make the load feel lighter.

MACHINE CHECK
  • Read the question.
  • Tap your answer.
What is the point a lever turns on?
Where should the load go to need less effort?
You pull down on a pulley string. Which way does the load go?
IdeaTrue or false?
A lever turns on a fulcrum.?
A simple pulley makes the load weigh less.?
A pulley lets you pull down to lift up.?
WHY THIS EXERCISEKnowing how each machine helps lets you pick the right one.
Look around
A seesaw is a lever.
People have used pulleys to lift water from wells.

Machines all around

  • A seesaw is a lever. The middle is the fulcrum.
  • Pulleys have been used to lift water from wells.
  • Both help people move loads.
LEVER OR PULLEY?
  • Read the question.
  • Tap your answer.
A board turns on a log. Lever or pulley?
A rope goes over a wheel to lift a bucket. Lever or pulley?
On a seesaw, where is the fulcrum?
What does a simple pulley change?
LIFT WITH A LEVER
  • Tap a card.
  • Then tap its spot.
1First
2Next
3Then
4Last
Try it
Lay a ruler across a round marker.
Put a small eraser on one end.
Press the other end gently. Watch the eraser rise.
Safety first
Press gently.
Keep faces away from the ruler ends.
Draw a lever. Label the fulcrum, the load and the push.

You met two simple machines!

Tomorrow, we build a lever.

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