Important announcement

Dear visitor,

Please note that this OpenCourseWare platform will be replaced at the end of 2026 by a new platform (under the same url ocw.tudelft.nl).

Courses and their contents that are currently available the platform will partly be migrated. URL’s for this content will change and content might be unavailable for some time. In addition, some courses will not be available anymore.

If you are linking to specific courses on this platform (for instance for your students), please take timely measures to avoid problems with access. Possible actions are:

Download the materials to your local platform (laptop, server)
For educators only (including TU Delft lecturers): Contact us at ocw@tudelft.nl and inform us what course you are using in what context (institute, program, period of use, number of students). We will research (in collaboration with the authors of the course) and decide if we will migrate the course, and if yes, can supply you with a new url.

Thank you.

Home Courses 2.3 The mechanical energy balance & Bernoulli’s law: exercise 1 (example) Course materials Lectures 2.3 The mechanical energy balance & Bernoulli’s law: exercise 1 (example)

2.3 The mechanical energy balance & Bernoulli’s law: exercise 1 (example)

STRAW IN A RIVER

In order to calculate the velocity of the water of a little brook in the Rocky Mountains, the following is done: a bent straw is partially placed beneath the water line (see figure). As the top of the straw is only 5 cm above the water line, water just starts to pour out a tiny little bit. You can assume that the outflow at the top is zero.

Now, we are going to make some calculations in order to find the flow speed in the water and the dynamic pressure. You may want to copy the sketch of the situation first. You might want to use the formula sheet.

[sg_popup id=6]