Question #ab711
1 Answer
A mass at least =340kg
Explanation:
I think, looking at the picture, that the question is what mass has to be placed over the
The question is based on Pascal's principle that states that pressure in a liquid is transmitted equally in all directions. We will need to assume that the lava behaves like a liquid.
Pressure is given by force divided by area, or
The boulder has a weight of 10,000N. hence a force exceeding this will need to be transmitted by the pressure in the fluid to move it.
The boulder is sitting on area of
If a weight,
exerted on the fluid below will be:
We need this pressure, which will be transmitted through the lava, to move the boulder so:
which simplifies to:
If we take
So they should put a mass of at least 340kg to enable them to push it off (provided they don't get fried by the molten lava first!)