Category - Force & Energy

Key Idea - Centre of Gravity

HOME  | SAFETY  | NEW | TEACHERS | PARENTS | CATEGORIES | LIST | AUTHOR

Copyright 2008 Ian Reed

ian-reed@science-wizards.com

Figure 1 - Arrangement of fork and spoon for Method 1

Figure 2 - Balancing cutlery Method 1

Figure 3 - Arrangement of fork s for Method 1

Figure 4 - Balancing cutlery Method 2

Balancing Cutlery

My favourite restaurant trick.

HOME  | SAFETY  | NEW | TEACHERS | PARENTS | CATEGORIES | LIST | AUTHOR

Purpose -

Can be used to demonstrate the centre of gravity. 

Nature - 

Demonstration

Materials - 

A spoon and two forks, a matchstick, a cork (not a rubber stopper), a nail, a retort stand

Method - 

Part 1 - Join a fork and spoon together as shown in Figure 1, and wedge the match between the tines of the fork. With a little effort you should now be able to balance the whole contraption on the tip of the retort stand.

Part 2 - Jam the 2 forks into the cork as shown in figure 3, and them jam the nail in the underside. This should also balance on the top of the retort stand.

Safety -

Fork wounds!

Explanation -

No matter what the shape of an object is, it can balance on it's centre of gravity. These unusual arrangements all obey this law by having a centre of gravity in an unusual place; the tip of the nail or match.

Notes -

The centre of gravity of an object can be found by hanging a object by one point and dropping a line from the point straight down, then doing it again from another point. Where the two lines cross is the centre of gravity.

This Wizard was generously supplied by Mr. Mark Bateman