# Warm-Up Exercise for lecture 19

## Due 8:00 am, Tues, 3 Nov 2009

Physics 105, Fall 2009

Enter your 3-digit class identification number:

Enter the last 4 digits of your BYU ID:

Did you complete the reading assignment? (Typically this means at least 20-30 minutes looking over the assigned sections of the book.)
☐ yes ☐ no

Water flows from a pipe with large diameter into a pipe with smaller diameter. The speed of the water in the small tube is
☐ greater than
☐ less than
☐ equal to
the speed in the large tube

Same situation. The pressure in the small tube is
☐ greater than
☐ less than
☐ equal to
the pressure in the large tube

A ping pong player puts "topspin" on the ball as he hits it to you by causing it to rotate such that the top of the ball is spinning towards you. Where will the ball strike the table compared to if it were not spinning?
☐ closer to you
☐ farther from you
☐ same distance

In the reading assignment for today, Ralph noticed two different equations labeled "Bernoulli's Equation". One said, "P1 + ½ r v12 + rgh1P2 + ½ r v22 + rgh2", the other said, "P + ½ r v2 + rgh = C". He wants to know how they can both be the same equation when they look so different. And what does C stand for, anyway? What can you tell him?

The comments in the next next two boxes go into a big, mostly anonymous text file that I skim through before the morning lecture, using the comments to help me plan class discussion. ("Mostly anonymous", because I can track down who made what comment, but it takes some effort on my part to do so.) Therefore, if you really want to make sure I see your question/comment and answer it individually, you should send it to me via email and not through this form.

Which part of today's assignment was particularly hard or confusing? What would you like to spend extra time on in class?