**Ten bricks, each 6.0 cm thick mass 1.5kg, lie flat on a table. How much work is required to stack them one on the top of another?**

__Problem No.4.3:-__

__Solution:-__

__Given Data:-__

__To Determine:-__
Work done by
placing them one on the top of another = W =?

__Calculation:-__
Now first of all
suppose that all bricks are on the ground. Now you lift a brick i.e.; 2

^{nd}and placed it on any one of them which is 1^{st}, now they are two bricks, after that you lift a third one and placed it on the other two, and so on.
Now think for a while that when you lift 2

^{nd}brick and placed it 1^{st}brick then 1^{st}brick remain on its place and you never do any work to lift it.
So, we conclude that we work done only on 9 bricks and not
on the 10

^{th}which is basically the 1^{st}brick.
Hence,

Total weight
of 9 bricks = w = mg

After that when you
manage the all of these bricks then, their height is 60cm but their combined
center of gravity is 30cm.

hi..Im college student, thanks for sharing :)

ReplyDelete