Question

Make a 50 cm v 50 cm bed of dry sand about I 0 cm in thickness. Make sure that its top surface is levelled. Take a wooden or a plastic stool. Cut two strips of graph paper each with a width of l cm. Paste them vertically on any leg of the stool—one at the bottom and the other from the top. Now gently put the stool on the sand bed with its legs resting on the sand Increase the size of sand bed if required. Now put a load, say a school bag full of books, on the seat of the stool. Mark the level of sand on the graph strip. This would give you the depth, if any, to which the legs of stool sink in sand. Next, tam the stool upside down so that now it rests on its neaten the sand bed. Note the depth to which the stool sinks now. Next,
put the same load on the stool and note the depth to which it sinks in the sand. Compare the pressure exerted by the stool in the two situations.​

Answer 1

Answer:

The choice of construction materials essentially depends on their suitability, their local availability and the amount of money you are prepared to invest.

3. If you are a beginner fish farmer and your farm is very small, it is best to use simple structures and not to spend too much on materials. As you gain experience and wish to expand, your investments may increase, and more permanent, better structures may be built.

4. It you plan to build a large fish farm, you should select the most suitable permanent structures from the start.