The Toppling Blocks

Observe the follow applet

Four blocks are stacked on a table. Each blocks can be considered of same mass, and uniform density. the blue number at the center of the blocks represent the distance of the block from the left border.

you can use the mouse left click to drag the blocks. try to move the top block towards the right.

you would realise the block changes from green to yellow to red as you drag it towards the right-hand side. the colors indicate how stable the blocks are:

Green:           very stable                                   

Yellow:          stable, but at the edge of toppling

Red:                it will fall in real life!                    

the task at hand is to move the top block as far right as possible without any blocks toppling.

How far is far enough?

What is the maximum distance did you manage to move the top block to? and why do you think that is the furthest distance possible?

what are the positions of other blocks?

How did you achieve that?

In what order did you move the blocks? and Why is that so?

Is there any pattern/boundary that you can refer to when you are moving the blocks?

To see the invisible

Click on "show c.g.". four arrows are shown. what do you thing these arrows represent?

Take into account this new information, again, is there any pattern/boundary that you can refer to when you are moving the blocks?

Conculsion

How does c.g. affects the stability of an object?

How do you, now, move the blocks to achieve the furthest distance possible?

Extras (Optional)

In what way will the blocks fall? Why?

Clone this page and fill in your answers. save the new page. use yourname_class (eg. Ben_1102) as the page name, put the page into your class folder

the simulation is used with permission from http://www.phy.ntnu.edu.tw/java/index.html