Tuesday, March 20, 2018

To Infinity and Beyond, dome test

 For the sky dome exam, are the students expected to know all the constellations on the sky chart posted to the WESO site (such as Monoceros and others) or only those listed on the other materials as constellations they need to understand?

Those that are listed on the instruction/description sheet for the event.

Write It/Build It

We have 2 writers for our Write it Build it team. Can they each write on a separate piece of paper at the same time and then both papers will go to the builders? 

The answer is yes.

Sunday, March 18, 2018

Water Rockets Questions

(Q1) In the Water Rockets study guide, the speed of sound is given as 660 mph.  However, at sea-level standard temperature, the speed of sound is 770 mph (this is roughly 660 nautical miles per hour).
A1) It is good to know how the speed of sound is related to the density of
the medium, and the ground distance covered at a given pressure and
temperature.  It might be best to ask oneself , "What question would
be asked to determine an understanding of this phenomenon."

Q1a)Regarding (1), my concern remains that the study guide specifically states 660 mph as Mach 1.  This statement should either be removed, since the speed of sound is not constant and depends on temperature via sqrt(gamma*R*T), or the correct value for the speed of sound should be given at STP conditions (most meaningful as a reference point).  This correct value is 770 miles per hour.

"Water Rockets" has a goal of introducing aerodynamics to students in Grade School.  It is understandable that rockets are more the realm of physics, and this is a compromise.

Pegging a ground speed to mach in mph is a problem.  Let me address.
Aeronautic terms are traditionally in knots, which can be also stated as Knph, and even as "miles per hour", but not as mph.  The 767mph or ~ 660 knots at 20C at 1 atm sounds about right, so I understand the confusion.  However sea level at room temp is not a common condition to attain Mach 1 in a vehicle with aerodynamic qualities, but is closer to the conditions of physics laboratories which explore properties of sound, etc.  When I look at the charts, I see that from 35,000 ft on up to 60,000 ft at ~ -56C mach equates to right about 660 mph. These are the common conditions to attain mach or better for such capable aircraft.
There is a secondary issue which is to make mach relative to a ground speed for a third grader.. Therefore knots or M/s are less desirable than mph.
The speed should stand at 660 mph.  While one could add specific atmospheric conditions, it would mean more memorization. 
(Q2) The material list specifies no metal parts.  Does that mean that even small metal pieces, such as paper clips, are not allowed?  I assume the answer is yes (not allowed), but I wanted to double-check.

A2: The only metal part allowed would be a fishing type swivel and or
clip.  The concern is the metal can become a dangerous projectile upon
bottle failure.  A metal paperclip falls in the category of dangerous
metal part at high speed.
(Q3) The event description states that "No other source of potential or kinetic energy to launch the rocket, eject the nosecone, or deploy the parachute will be permitted".  However, rubber bands are listed as an allowed material.  Is the potential energy of a stretched rubber band exempt from the "other source" of energy rule?

A3. A rubber band is allowed, but it may only be stretched by the
motion of the rocket after launch.  An argument could be made for a
release mechanism using a pre-stretched rubber band, however, if the
result increases the kinetic energy in a desirable direction for any
of rocket parts, it should not be allowed.  The most probable use of
such a device would be to seperate the nosecone in a positive
direction, and/or deploy the parachute more rapidly.  I would
personally rule against this use currently  though others may chime


Will there be any Potions workshops offered?

No, there will not be a Potions workshop.
Also, my fellow coach and I signed up after the coaches meeting earlier in the year, are there any opportunities to get a little more training?  I see Emily & Michael Briggs are the supervisors for Potions, but there is no contact information listed for them.

Any questions that you have, please send to this e-mail address- weso.science@gmail.com  . The answers will be sent back to you directly, and also posted on the updates blog for all coaches to see.
Updates Blog

Saturday, March 17, 2018

Compete only at your grade level.


Can a 4th grader also compete in a 5th grade event since we have no 5th graders doing certain events? 

No, playing up or down is against the Olympiad rules.