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Archimedes principle

  • Thread starter suzukits
  • Start date
  • #1
8
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Homework Statement



A solid cube of foam plastic has a volume of 25m^3 and a density of 800kg/m^3. How large a force is required to hold it under water?

Homework Equations


P = F/A
Fb = ρgV
ρ = m/V

The Attempt at a Solution


ρ = m/V
800 = m / 0.000025
m = 0.02kg

so F = mg = 0.02 x 9.8 = 0.196
I understand that the force required to keep it under water will be greater than this but I'm having a hard time finding the right equation.
 

Answers and Replies

  • #2
8
0
anyone ?
please
 
  • #3
1,197
0
For starters look at the equation below that I copied.

800 = m / 0.000025

You have an error with your units.

Are you familiar with Archimedes Principle? If so, please state it.
 

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