Physical Science & Chemistry

Materials Science

Wind Power - Div C

Hovercraft - Div C

(section: 1 / line: 1)

2016-11-07 19:05 Description state "MAY construct". Can students use commercial kits or models or should they be built "from scratch".

Commercial kits may be used, as long as the SO building policy is followed: https://www.soinc.org/building_tools_policy

(section: 2, 3 / paragraph: 5, 6 / sub-paragraph: f, b / line: 1,1)

2016-11-07 19:04 In Section 2, paragraph 5, sub paragraph f, the rules mention a target time and then identify it for C only. In section 3, paragraph 6, subparagraph b, the scoring says the time score gives a calculation involving a target time. Please clarify.

5.f. doesn't identify the target time for C only. It only mentions that the target length will be announced for Div. C only (since Div. B already knows the target length). The target time concept applies to both B and C. The reference to Div C is for the variable length that must be announced.

(section: 4 / paragraph: b / line: 1-2)

2016-11-07 20:25 Is the maximum dimensions of the skirt 19.5 x 30 cm when the hovercraft is inflated or deflated? Can the skirt be larger than those dimensions when the motor is not running?

The maximum dimension of the skirt is the same as the device, 19.5 cm wide x 30 cm long, both inflated and deflated. Students may tuck the uninflated skirt under the device prior to inflation.

(section: 4 / paragraph: e / line: 1)

2016-11-07 20:28 Please define what the propeller shielding is (1/4 in diameter?).

The propeller(s) must be enclosed in such a way that there are no holes bigger than 1/4" in diameter in the enclosure. A 1/4" dowel rod must not be able to penetrate the material.

(section: 4 / paragraph: g / line: 1)

2016-11-14 21:25 The 1/4" or larger dowel. Can any material be used (i.e. wood, plastic, metal), and must it be solid or can it be an optically opaque tube meeting the specified dimensions and purpose of breaking a light beam?

The dowel can be any material, but by definition a dowel is a solid cylindrical rod, hence a straw is not allowed.

(section: 4 / paragraph: h / line: 1)

2016-11-07 19:10 Can we connect two 9V batteries in parallel? Voltage across any points will not exceed 9V as they are connected in parallel. This just gives us higher current capacity to drive two motors.

Yes, this would be allowed.

2016-11-07 19:12 Is the total voltage for the hovercraft 9V, or is 9 volts the maximum rated for each circuit? For example, may I have a separate 9V battery for each motor if they are not linked?

Yes, multiple batteries may be used as long as they are not connected in such a way that the voltage exceeds 9 V in any circuit. Separate 9 V circuits are allowed.

(section: 4 / paragraph: i / line: 1)

2016-11-07 19:19 Is a breadboard with resistors and/or transformers considered and integrated circuit?

No. A breadboard with discrete resistors and/or basic transformers is not an integrated circuit. Note though that some types of resistors and transformers ARE integrated circuits and hence are not allowed.

2016-11-07 19:26 The clarification on this rule is not entirely clear. If I found a commercially-available product containing a brushless motor attached to a fan, must it be labeled as a "cooling fan" to be legal?

No. As long as it is a fan typically used for cooling electronics or computers it does not need to be labeled as such.

2016-11-07 19:29 Is an Arduino an integrated circuit?

Yes, an Arduino contains many integrated circuits and is not legal.

(section: 4 / paragraph: i / sub-paragraph: n/a / line: 1)

2016-11-07 19:27 What constitutes an integrated circuit?(ie. are resistors, capacitors, transistors allowed? Operational Amplifiers?)

An integrated circuit is a circuit in which all or some of the circuit elements are inseparably associated and electrically interconnected so that it is considered to be indivisible for the purposes of construction and commerce. Most resistors and capacitors are not integrated circuits. Nearly all transistors and op-amps are integrated circuits.

(section: 4 / paragraph: i / sub-paragraph: N/A / line: 1)

2016-11-07 19:56 Do commercially available switches, such as dimmer switches, count as integrated circuits?

It depends on the specific switch. Some switches are purely mechanical (i.e. utilize a potentiometer) and are allowed. Others are digital (i.e. utilize an integrated circuit) and are not allowed.

(section: 4 / paragraph: j / line: 1)

2016-11-07 20:10 For the definition of a "cushion of air": does the air have to have a way out of the cushion on the bottom or sides, or can it be designed similar to an air mattress?

Yes because it is not hovering unless air is coming out. The air must have some way of escaping (i.e. it should need to be actively replenished for the device to work, not just be a sealed inflatable chamber).

(section: 4 / paragraph: j / line: 4)

2016-11-07 20:07 How high must the hovercraft hover?

There is no set distance it must hover. If an event supervisor, from a normal observation point without having to get up and close to the hovercraft, can visually see it move down when pushed, then yes it levitates.

(section: 4 / paragraph: k / line: 1)

2016-11-07 19:17 Can teams use a remote control to start and/or stop their hovercraft?

No, as any remote control system would violate either the dimension requirements or the prohibition on integrated circuits.

(section: 5 / paragraph: f / sub-paragraph: N/A / line: 1)

2016-11-07 19:53 Is there an interval for the target time of the competition. Ex-- between 5.0-25.0s in intervals of 1 second

No

(section: Constr / paragraph: i / line: 1)

2016-11-07 19:55 The rules say that Brushless motors and integrated circuits are not permitted, does this just refer to integrated circuits to control motors or things like adjustable voltage regulators and arduinos.

Note there is an official rules clarification related to this, available at: https://www.soinc.org/official_rules_clarif The integrated circuit prohibition refers to all components (including voltage regulators / arduinos) other than those specified in the rules clarification.

Forensics

Optics

Chem Lab