Simple Machines Worksheets - Free Printable

Let’s go step by step to figure out the class of each lever and label its parts (A, B, C).

First, remember:
- A lever has three main parts:
→ Fulcrum (the pivot point)
→ Effort (where you push or pull)
→ Load (what you’re trying to move or lift)

There are three classes of levers:

🔹 Class 1: Fulcrum is between Effort and Load.
Example: Seesaw, scissors

🔹 Class 2: Load is between Fulcrum and Effort.
Example: Wheelbarrow, nutcracker

🔹 Class 3: Effort is between Fulcrum and Load.
Example: Tweezers, fishing rod

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

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1. Tweezers

- You squeeze in the middle (that’s the effort).
- The tips hold something (that’s the load).
- The end where they’re joined is the fulcrum.
→ So, Effort is between Fulcrum and Load → Class 3

Labeling:
- A = Fulcrum (joint at the back)
- B = Effort (where you press)
- C = Load (tips holding object)

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2. Scissors

- Pivot (fulcrum) is in the middle.
- You apply effort on the handles.
- Blades cut the load.
→ Fulcrum is between Effort and Load → Class 1

Labeling:
- A = Fulcrum (screw/pivot)
- B = Effort (handles)
- C = Load (blades cutting)

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3. Nutcracker

- You squeeze the handles (effort).
- The nut is in the middle (load).
- The hinge at the end is the fulcrum.
→ Load is between Fulcrum and Effort → Class 2

Labeling:
- A = Fulcrum (hinge)
- B = Load (nut)
- C = Effort (handles)

Wait — actually, looking at how it’s drawn: usually, for a nutcracker like this, the fulcrum is at one end, the load (nut) is near the middle, and effort is applied at the other end. So yes — Class 2.

But let’s double-check labeling based on typical diagram positions:

In most diagrams:
- A = Fulcrum
- B = Load
- C = Effort

So for nutcracker:
- A = Fulcrum (pivot at end)
- B = Load (nut position)
- C = Effort (where hands squeeze)

Yes.

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4. Balance Scale (like old-fashioned scales)

- The beam pivots in the center → that’s the fulcrum.
- Weights or objects go on both ends → those are loads.
- But since we’re applying force to balance, technically, one side is effort, one is load? Actually, in a balanced scale, both sides are loads — but for lever classification, we consider one side as effort if we’re lifting.

Actually, think of it this way: when you put an unknown weight on one side and known weights on the other, you’re using the known weights as “effort” to balance the “load”.

But more accurately — in a balance scale, the fulcrum is in the middle, and both arms have loads. However, for lever class purposes, it’s still considered Class 1, because fulcrum is between two forces.

So:
→ Class 1

Labeling:
- A = Fulcrum (center pivot)
- B = Load (one pan)
- C = Effort (other pan — or vice versa; doesn’t matter which is which as long as fulcrum is in middle)

Typically:
- A = Fulcrum
- B = Load
- C = Effort

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5. Fishing Rod

- You hold the bottom (fulcrum).
- You pull up with your hand somewhere along the rod (effort).
- The fish at the end is the load.
→ So, Effort is between Fulcrum and Load → Class 3

Labeling:
- A = Fulcrum (bottom of rod, held against body)
- B = Effort (hand pulling up)
- C = Load (fish at tip)

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6. Wheelbarrow

- Wheel is the fulcrum (at front).
- Load (dirt, etc.) is in the bucket (middle).
- You lift the handles (effort at back).
→ Load is between Fulcrum and Effort → Class 2

Labeling:
- A = Fulcrum (wheel axle)
- B = Load (bucket contents)
- C = Effort (handles you lift)

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Now let’s compile all answers clearly.

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Final Answer:

1. Tweezers
Type: Class 3
A: Fulcrum
B: Effort
C: Load

2. Scissors
Type: Class 1
A: Fulcrum
B: Effort
C: Load

3. Nutcracker
Type: Class 2
A: Fulcrum
B: Load
C: Effort

4. Balance Scale
Type: Class 1
A: Fulcrum
B: Load
C: Effort

5. Fishing Rod
Type: Class 3
A: Fulcrum
B: Effort
C: Load

6. Wheelbarrow
Type: Class 2
A: Fulcrum
B: Load
C: Effort