Exam2_2010_solution

# Exam2_2010_solution - 57:020 Mechanics of Fluids and...

This preview shows pages 1–2. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 57:020 Mechanics of Fluids and Transport Fall 2010 EXAM2 Solutions Problem 1: Momentum equation (Chapter 5) Information and assumptions • 1 = 760 kPa; 2 = = 101 kPa • 1 = 5 cm; 2 = 2 cm • ρ = 788.42 kg/m 3 for alcohol • No losses in the nozzle flow Find • Alcohol jet velocity V 2 and the force F required to hold the plate stationary Solution (a) As no losses in the nozzle flow, one can apply the Bernoulli equation between the sections 1 and 2 to find 2 . By knowing that 1 = ( 2 1 ⁄ ) 2 = ( 2 1 ⁄ ) 2 2 from the continuity equation and that 1 = 2 , the Bernoulli equation can be written as 1 + 1 2 ¡ 2 1 ¢ 2 2 £ 2 = 2 + 1 2 2 2 (+3 points) or 2 = ¤ 2( 1 − 2 ) [1 − ( 2 1 ⁄ ) 4 ] Thus, 2 = ¥ 2(760,000 Pa − 101,000 Pa) ¡ 788.42 kg m 3 ¢ [1 − (0.02 m 0.05 m ⁄ ) 4 ] = 41.42 m s ⁄ (+2 point) (b) For a control volume that encompasses the jet from section 2 and the plate, a momentum analysis gives − = − ̇ ( 2 ) + 0 = − 2 2 2 (+4 points) Thus, =...
View Full Document

{[ snackBarMessage ]}

### Page1 / 4

Exam2_2010_solution - 57:020 Mechanics of Fluids and...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online