BALANCING FROG

Frog balancing with weights

Materials in the Box:

1. Pre-cut Balancing Frog 
2. Pivot point piece (1 cm hole plug)
3. Foam base
4. Pipette tip

Materials from home:

1. Hole puncher (optional)
2. Paper clips
3. Pennies
4. Pencil

How do I begin?

1. You can punch a hole with a hole punch in the frog’s head, centered and near the edge. Figure 2. Insert the pivot point (plug) into the hole in the frog's head. Secure the plug well by pushing down around the edges of the hole. Figure 3 (side view).
   
   
2. Make a base by piercing a hole in a piece of foam and inserting a pipette tip
   
   
3. Optional – Use a pen or small bits of paper to make “eyes.”  
   
   
4. Investigate how to get the frog to balance on the pivot point.
   
   
5. Add weights to the frog using paperclips. Where do the weights need to be positioned? Try balancing the frog on the stand, on a pencil, your finger, or your nose!
   
   
6. Once you find the best locations the frog should be positioned in, replace the paperclips with other weights, like pennies, attached to the underside of the frog’s feet. This will make the weights less noticeable.
   
   

What just happened?

An object balances on a point if that point is aligned with the object’s center of mass. A flat object 
(like a paper frog) would normally balance at its geometric center. Adding weight to the frog’s front feet 
changes its weight distribution, moving its center of mass closer to its head.

Pipette insertion sequence

Frog balancing on pipette