Simple Machines Worksheet - Identify lever classes and label effort, resistance, and fulcrum forces.

Let’s go step by step to solve this worksheet.

We’re working with levers — simple machines that help us lift or move things easier. Every lever has three parts:
- Fulcrum (F): the pivot point (where the lever turns)
- Effort force (E): where you push or pull
- Resistance force (R): the load or weight you’re trying to move

There are 3 classes of levers, based on where these 3 parts are placed:

🔹 Class 1: Fulcrum is between Effort and Resistance
→ Example: seesaw, scissors

🔹 Class 2: Resistance is between Fulcrum and Effort
→ Example: wheelbarrow, bottle opener

🔹 Class 3: Effort is between Fulcrum and Resistance
→ Example: tweezers, fishing pole, broom

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Now let’s look at each diagram one by one.

Diagrams 1–4 (simple lever drawings)

Diagram 1:
- Arrow down on left = effort (you’re pushing down)
- Triangle in middle = fulcrum
- Box on right = resistance (load)
→ Fulcrum is between effort and resistance → Class 1

Diagram 2:
- Arrow up in middle = effort (lifting up)
- Triangle on left = fulcrum
- Box on right = resistance
→ Resistance is between fulcrum and effort? Wait — no! Actually, effort is in the middle, fulcrum on left, resistance on right → So effort is between fulcrum and resistance → Class 3

Wait — let’s double-check:
In Class 3, effort is between fulcrum and resistance. Yes — here, fulcrum (left), then effort (middle arrow up), then resistance (right box). So yes — Class 3

But hold on — if you’re lifting UP in the middle, and the fulcrum is on the left, and the load is on the right… that means you’re applying effort between fulcrum and load → still Class 3.

Actually, let me think again — maybe I got it backwards.

Standard rule:
- Class 1: F between E and R
- Class 2: R between F and E
- Class 3: E between F and R

So for Diagram 2:
Left: fulcrum (triangle)
Middle: upward arrow → that’s effort (you’re pulling up)
Right: box → resistance

So order from left to right: F — E — R → so E is between F and R → Class 3

✔ Correct.

Diagram 3:
Triangle (fulcrum) on left
Box (resistance) in middle
Upward arrow (effort) on right

Order: F — R — E → so resistance is between fulcrum and effort → Class 2

Diagram 4:
Triangle (fulcrum) on left
Box (resistance) on left side? Wait — box is on left, fulcrum under it? No — looking again:

Actually, in Diagram 4:
- Fulcrum (triangle) is under the beam, closer to left
- Box (resistance) is on the LEFT end
- Downward arrow (effort) is on the RIGHT end

So positions:
Left: resistance (box)
Middle-left: fulcrum
Right: effort (down arrow)

So order: R — F — E → fulcrum is between resistance and effort → Class 1

Wait — but usually we list from left to right as they appear.

Actually, position doesn’t matter — what matters is relative placement.

If fulcrum is between effort and resistance → Class 1.

Here: resistance (left), fulcrum (under beam near left), effort (right) → so fulcrum is between them → Class 1

Yes.

So summary for 1–4:

1. Class 1
2. Class 3
3. Class 2
4. Class 1

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Question 5: Which lever would be most efficient at lifting a heavy block of granite?

Efficiency for lifting heavy loads → we want mechanical advantage > 1 → meaning less effort needed.

Class 2 levers give mechanical advantage because the effort arm is longer than the resistance arm → you can lift heavy things with less force.

Looking back:

Diagram 3 is Class 2 → resistance in middle, effort far away → long effort arm → good for lifting heavy things.

Also, Diagram 2 is Class 3 → that gives speed/distance, not strength — bad for heavy loads.

Diagram 1 and 4 are Class 1 — depends on where fulcrum is. In Diagram 1, fulcrum is centered? Not sure — but typically, if fulcrum is close to load, you get advantage.

But among all, Class 2 is BEST for lifting heavy objects.

So answer: Diagram 3

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Now diagrams 6–11 — real-life tools.

6. Bottle Opener

How it works: You hook under cap (resistance), pivot on edge of bottle (fulcrum), push down on handle (effort).

So: fulcrum at tip, resistance under cap, effort at handle → resistance is between fulcrum and effort → Class 2

Labeling: Draw line — fulcrum at very end touching bottle, resistance under cap, effort at your hand on handle.

Monikers: F at pivot, R under cap, E at handle.

7. Pliers

Two levers joined. Each side: you squeeze handles (effort), jaws grip object (resistance), pivot in middle (fulcrum).

So fulcrum in center, effort on handles, resistance at tips → fulcrum between effort and resistance → Class 1

Label: F at pivot screw, E at handles, R at jaws.

8. Broom

When sweeping: you hold top with one hand (fulcrum), other hand pushes middle (effort), bristles sweep floor (resistance).

So: fulcrum at top hand, effort in middle, resistance at bottom → effort between fulcrum and resistance → Class 3

Label: F at top hand, E at lower hand, R at bristles.

9. Fishing Pole

You hold bottom (fulcrum), reel or hand applies effort near bottom, fish pulls at tip (resistance).

Actually: when reeling in, you hold rod near base (fulcrum), apply effort with hand above that, resistance is fish at tip.

So: fulcrum at bottom, effort in middle, resistance at tip → effort between fulcrum and resistance → Class 3

Label: F at butt end, E where you grip to lift, R at hook/fish.

10. Seesaw

Classic example: two people on ends, pivot in middle → fulcrum between effort and resistance → Class 1

Label: F at center pivot, E and R at each end (depending who is pushing down).

11. Wheelbarrow

Wheel is fulcrum, load (dirt) in bucket is resistance, you lift handles (effort).

So: fulcrum at wheel, resistance in middle (bucket), effort at handles → resistance between fulcrum and effort → Class 2

Label: F at wheel axle, R in bucket, E at handles.

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Now let’s compile all answers clearly.

Final Answers:

1. Class 1
2. Class 3
3. Class 2
4. Class 1
5. Diagram 3 (because it’s a Class 2 lever, which gives mechanical advantage for lifting heavy objects)
6. Bottle Opener → Class 2
7. Pliers → Class 1
8. Broom → Class 3
9. Fishing Pole → Class 3
10. Seesaw → Class 1
11. Wheelbarrow → Class 2

For labeling F, R, E on diagrams 6–11 — since we can’t draw here, I’ll describe:

6. Bottle Opener:
- F: point touching bottle rim
- R: under bottle cap
- E: where you press down on handle

7. Pliers:
- F: pivot screw in middle
- E: where you squeeze handles
- R: tips gripping object

8. Broom:
- F: top hand holding broom
- E: lower hand pushing
- R: bristles on floor

9. Fishing Pole:
- F: bottom end held against body/hand
- E: hand gripping rod to lift
- R: fish at end of line

10. Seesaw:
- F: center support
- E: person pushing down on one side
- R: person being lifted on other side (or vice versa — both sides can be E or R depending on action)

11. Wheelbarrow:
- F: wheel axle
- R: load in bucket
- E: hands lifting handles

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Final Answer:

1. Class 1
2. Class 3
3. Class 2
4. Class 1
5. 3
6. Class 2
7. Class 1
8. Class 3
9. Class 3
10. Class 1
11. Class 2