💨 Hovercraft Mock Exam

What is the maximum size constraint for a hovercraft in the 2026 Science Olympiad Hovercraft event (measured with skirt inflated)?

How many participants are allowed per team during the Hovercraft event?

What is the minimum height the timing dowel must extend above the track surface, and where must it be positioned on the craft?

Which of the following wiring practices constitutes a construction violation resulting in a score of 0?

During post-run inspection, an event supervisor finds that a team's propeller shield has a gap large enough for a 3/8" dowel to contact the blades. What is the most likely outcome?

Pascal's Law states that pressure applied to an enclosed fluid is:

A hovercraft base has an area of 0.05 m². If the air cushion maintains a gauge pressure of 200 Pa above atmospheric, what is the total upward lift force produced?

Bernoulli's principle describes the relationship between fluid speed and pressure. Which statement correctly applies Bernoulli's principle to a hovercraft fan blade?

When a hovering hovercraft is at equilibrium (constant hover height), which statement best describes the air cushion dynamics?

The continuity equation for incompressible flow (A₁v₁ = A₂v₂) predicts that when airflow moves from a wider duct section into a narrower one, the air velocity:

Which two forces primarily resist a hovercraft's forward motion during a run?

A hovercraft weighs 10 N. If the pressurized air cushion must support this weight over a base area of 0.04 m², what minimum gauge pressure must the air cushion maintain?

The boundary layer in aerodynamics refers to:

According to Newton's Third Law, how does a thrust fan propel a hovercraft forward?

A hovercraft design requires a fan to generate high static pressure at relatively low airflow volume to keep the skirt inflated. Which fan type is most appropriate?

CFM (cubic feet per minute) is the standard rating for hovercraft fans. What does CFM measure?

The Science Olympiad Hovercraft rules require all propellers and impellers to be shielded so that a 3/8" dowel cannot contact the blades. What is the PRIMARY purpose of this requirement?

The Coandă effect is exploited in some advanced hovercraft skirt designs. This effect describes the tendency of:

A single-propeller hovercraft tends to rotate (yaw) in one direction during operation, even without intentional steering input. What is the primary cause?

A thrust fan produces 2.4 N of thrust. The craft's weight is 9.6 N and is fully supported by the air cushion. What is the thrust-to-weight ratio?

A dual-motor hovercraft uses two counter-rotating propellers. Compared to a single propeller design with the same total thrust, what is the primary aerodynamic/mechanical benefit?

A hovercraft starts from rest and accelerates uniformly. After 5 seconds, it is moving at 1.5 m/s. What is its acceleration?

Newton's First Law (Law of Inertia) applied to a hovercraft on a near-frictionless air cushion means:

A hovercraft with a mass of 0.6 kg experiences a net thrust force of 1.5 N after drag losses. What is the craft's acceleration?

When sizing motors for a hovercraft, Newton's Second Law (F = ma) directly informs the team that:

Impulse-momentum theorem states that impulse (F·Δt) equals change in momentum. How is this most directly applicable to hovercraft design?

A hovercraft motor delivers 8 W of useful mechanical power. The craft moves at constant velocity of 1.6 m/s. What is the total resistive drag force (skirt friction + aerodynamic drag) acting on the craft?

A hovercraft starts from rest and travels 4.5 m down a track in 6.0 seconds under constant acceleration. What is the craft's acceleration?

According to Ohm's Law (V = IR), if a thrust motor circuit has a total resistance of 4 Ω and is powered by a 8.4 V battery, what current flows through the circuit?

Which battery type is specifically PROHIBITED by 2026 Science Olympiad Hovercraft rules?

A team connects their lift motor and thrust motor in series to a single 9 V battery. Each motor has equal impedance. What voltage does each motor receive?

A potentiometer is wired in series with the thrust motor. When the potentiometer's resistance is increased, what happens to the motor?

A NiMH battery pack is rated at 8.4 V / 4200 mAh. If both lift and thrust motors together draw a constant 3.5 A, approximately how long will the battery last under ideal conditions?

A team wants to use brushless motors for better efficiency. What important rule governs the use of brushless motor controllers (ESCs) in the Hovercraft event?

A thrust motor draws 4 A continuously. The team wires it with 28 AWG wire, which is rated for approximately 0.5 A. What is the most likely consequence during a competition run?

What is the primary function of a hovercraft skirt?

Which description best characterizes a bag skirt design?

Compared to a bag skirt, what is the primary performance advantage of a well-executed wall (peripheral jet) skirt?

When selecting a skirt material, which property is most critical for minimizing drag during a competition run?

A momentum curtain skirt design is considered more advanced than a standard bag skirt. How does it differ from a simple bag skirt?

Some teams modify their bag skirts by poking small holes in the bottom surface. What is the engineering rationale for this hole-pattern technique?

Why is precise speed control essential in the Hovercraft competition event?

During calibration, a team finds their craft runs approximately 15% too fast on a given potentiometer setting. To reduce speed, they should:

A team calibrates their hovercraft using a fully charged 8.4 V NiMH battery and achieves a perfect run time. On competition day, the battery has been sitting partially discharged at approximately 7.8 V. How will this affect the run?

During testing on smooth vinyl, a team's hovercraft completes the 5-meter track in 9 seconds. On the competition day rough concrete track, they observe the same potentiometer setting produces a run taking 12 seconds. What is the most likely cause and appropriate adjustment?

Which combination of properties makes foam core board a popular choice for hovercraft base construction?

Although the 2026 rules have no hard mass limit for hovercrafts, why should teams still minimize vehicle weight?

A team places their heavy NiMH battery pack at the very rear of the hovercraft to shift weight back. During testing, the craft consistently tilts nose-up and the rear skirt drags on the ground. What is the most likely explanation?

A team is choosing between balsa wood and 3D-printed PLA for their lift fan duct. Balsa has a density of ~160 kg/m³; PLA has a density of ~1,240 kg/m³. For equal-volume parts, PLA is approximately how much heavier than balsa?

A team uses JST quick-disconnect connectors at all fan and battery attachment points (modular design). What is the primary competitive advantage of this approach during the testing phase?

After completing a test run, what should a team do FIRST before making any changes to the hovercraft?

Between two consecutive test runs, a team simultaneously changes the skirt material (from Tyvek to Mylar) AND increases the potentiometer resistance. The second run is noticeably faster. What is the major problem with this approach?

A hovercraft lifts off cleanly during testing but immediately drifts sideways. Which factor is LEAST likely to cause lateral drift?

A team notices their hovercraft runs progressively slower with each successive test session (10-minute rest between sessions), and within each run it starts fast then slows down. The skirt appears intact and the fan settings haven't changed. What is the most probable cause?

Christopher Cockerell's invention of the modern hovercraft was demonstrated by which historic crossing?

Military hovercraft such as the US Navy's LCAC (Landing Craft Air Cushion) offer which primary operational advantage over conventional landing craft?

A Science Olympiad hovercraft weighs ~0.5 kg; a full-size military hovercraft weighs ~150,000 kg. Which scaling challenge is PROPORTIONALLY more significant for the small-scale craft?

What happens to a Science Olympiad team if they miss the designated impound window for the Hovercraft event?

During pre-run setup, a team discovers their timing dowel is wobbly and could drop below the required 20 cm height once the craft is powered on. The event proctor is present. What is the correct course of action?

A team has used one of their two run attempts and earned 75 points (run scored on distance+time). They believe their craft has a 70% chance of scoring 100 points on the next attempt (and a 30% chance of failure = 0 points). The event keeps the BEST single run score. Should they attempt the final run?