announcements common exam 3 is on monday. usual time and locations today’s material will not be on...
TRANSCRIPT
Announcements
• Common Exam 3 is ON Monday. Usual time and locations
• Today’s material WILL NOT BE on the exam.• Historically, Fluid Dynamics has NOT been
covered in Phys 111. You typically will NOT see examples of it on old exams.
• We have class on TUESDAY next week…. Tuesday follows a THURSDAY schedule.
• Due date for HW for TODAYS material is first Thursday in December.
• HW 13 AND HW 14 are due Reading day.
Iclicker Question #1
Why do golf balls have dimples on their surface?
A) It is more stylish than a smooth surfaceB) The golf balls roll straighter when putting on the greenC) The dimples reduce the air drag making the golf ball travel furtherD) The dimples increase the air drag limiting the travel distance so
that golf courses do not need to be to largeE) The dimples create a lifting force which makes the golf ball travel
further
Iclicker Question #2
What is the world record depth of a free dive (no breathing apparatus) with fins?
A) 30mB) 50mC) 61mD) 101mE) 128m
Iclicker Question #2
What is the world record depth of a free dive (no breathing apparatus) with fins?
A) 30mB) 50mC) 72m – Nov 17th, 2013 – Brooklyn Diver died on an attempt without
oxygen or fins.D) 101m – Women’s recordE) 128m – Men’s record
Technical Issues: (a) Pressure of water on human body compresses lungs. (b) body is oxygen deprived.
Static Equilibrium
0yF ma
Pascal’s Law
Manometer
Archimede’s principle
Eureka!
Fluid exerts an upward force on a body equal to the weight of the fluid displaced
by the body
Iclicker Question #2
Which statement is true regarding the pressures and velocities of a liquid flowing in the tube below?
A) The pressures at point 1 and point 2 are equal.B) The velocities at point 1 and point 2 are equal.C) The velocity at point 1 is larger than point 2, but the pressure is
smaller at point 1 compared to point 2.D) The velocity and pressure are higher at point 2 compared to point 1E) The velocity is higher at point 2, but the pressure is lower at point 2
12
Flow lines and continuity equation
1 1 2 2Av A v
Deriving Bernoulli’s Equation
Iclicker Question #3
For water in an open water tank, what is the velocity of the water which escapes from the bottom?
A)
B)
C)
A1
A2
H
222
2 1
21 ( / )
gHVA A
22 2V gH
D) It depends on the mass density of water
E) Can not be determined without knowing the velocity of water at the top of the tank
22 2atmV P gH
Lift of airplane wing
2 21 1
2 2L L u UP V P V
Since Velocity under wing is lower than velocity above wing, pressure below must be higher then pressure above
Net force = (PL-Pu) Awing
Viscous flow in a pipe
Laminar versus Turbulent flow
Golf ball
Golf Ball Trajectory
Top spin on a tennis ball (or sinker ball pitch)
What are your plans for the Summer?
A) Go on vacationB) Take classesC) Get a jobD) Do absolutely nothingE) I have not thought about it yet
ICLICKER
Think about a RESEARH EXPERIENCE
• Paid positions• Looks good on a resume• Experience practice application of your major• Perhaps you are thinking about pursuing Master’s or PhD?
Options:•National Science Foundation – Research Experience for Undergraduates (REU). Apply Now http://www.nsf.gov/crssprgm/reu/reu_search.jsp •Summer positions with local companies – Speak with your advisor or Career Services•Positions at NJIT – Do faculty in your department have NSF funding? They can get Summer REU support for you.•Provost’s Summer Research Programhttp://www.njit.edu/provost/events/undergrad_research.php NOTE: Contact person will be different this year. Apply in Spring Semester