P15_026 - numerical uncertainties associated with that...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
26. (a) The pressure (including the contribution from the atmosphere) at a depth of h top = L/ 2 (corre- sponding to the top of the block) is p top = p atm + ρgh top =1 . 01 × 10 5 + (1030)(9 . 8)(0 . 300) = 1 . 04 × 10 5 Pa where the unit Pa (Pascal) is equivalent to N/m 2 . The force on the top surface (of area A = L 2 = 0 . 36 m 2 )is F top = p top A =3 . 75 × 10 4 N. (b) The pressure at a depth of h bot =3 L/ 2 (that of the bottom of the block) is p bot = p atm + ρgh bot =1 . 01 × 10 5 + (1030)(9 . 8)(0 . 900) = 1 . 10 × 10 5 Pa where we recall that the unit Pa (Pascal) is equivalent to N/m 2 . The force on the bottom surface is F bot = p bot A =3 . 96 × 10 4 N. (c) Taking the diFerence F bot F top cancels the contribution from the atmosphere (including any
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: numerical uncertainties associated with that value) and leads to F bot − F top = ρg ( h bot − h top ) A = ρgL 3 = 2180 N which is to be expected on the basis of Archimedes’ principle. Two other forces act on the block: an upward tension T and a downward pull of gravity mg . To remain stationary, the tension must be T = mg − ( F bot − F top ) = (450)(9 . 8) − 2180 = 2230 N . (d) This has already been noted in the previous part: F b = 2180 N, and T + F b = mg ....
View Full Document

This note was uploaded on 11/12/2011 for the course PHYS 2001 taught by Professor Sprunger during the Fall '08 term at LSU.

Ask a homework question - tutors are online