Hovercraft

Science Olympiad

Division B

Team Name: ______Team Number: ______

Student Names: ______

Instructions:

  1. You have up to 20 minutes only to take this test.
  2. Please write your answers rounded to 3 decimal places. Do not use significant figures when rounding.
  3. You may take apart the test, but please put the pages in order before turning in.
  4. Please write legibly and make sure your answers are clearly indicated. Answers must have the correct units. No partial credit is given.
  5. Please use the approximation of 9.8 m/s2 for the acceleration of gravity.
  6. Each question is worth one point for a total of 30 points.
  1. What is the SI unit for impulse?

For questions 2, 3, and 4: Which of Newton’s Laws of Motion explains the situation?

  1. When pushed with the same amount of force, a more massive goat will accelerate at a slower rate than a less massive one.
  1. If you have an endless, frictionless surface and no air resistance, a kicked pig will slide forever.
  1. If you jump out of a boat, the boat will move in the opposite direction of you.
  1. A single 4 N force is acting on a rock, causing it to accelerate at a rate of 10 m/s2. What is the mass of the rock? (round to 3 decimal places as needed)
  1. What force is needed to accelerate a 0.6 kg apple pie at 9.3 m/s2? (round to 3 decimal places as needed)
  1. Why will an object launched into empty space travel forever (assuming no obstructions), but an object launched within the Earth’s atmosphere will eventually come to a stop? (Hint: the answer is not gravity)
  1. At what point will the vertical velocity of a projectile launched at a 60 degree angle be zero?
  2. Immediately after launch
  3. At the highest point of the trajectory
  4. Since it was launched at an angle, the vertical velocity cannot be determined
  5. Never
  1. What is the difference between velocity and speed?
  1. An elephant is dropped from the top of a 8 meter building. What is the elephant’s speed when it hits the ground? (round to 3 decimal places as needed)
  1. A limo is traveling at 7 m/s. It then accelerates at a rate of 5 m/s2 for 3 seconds. How fast is the limo going now? (round to 3 decimal places as needed)
  1. You are planning a walk with your friends and you want to know approximately how long it will take to get to the beach. What is the most accurate way to determine this?
  2. Determine how many miles away the beach is and divide by your average walking speed.
  3. Take your average walking speed and multiply by the number of miles to the beach.
  4. Determine the length of the path to the beach and divide by your average walking speed.
  5. Determine the length of the path to the beach and multiply by the length of your average step.
  1. What is the kinetic energy of a 5 kg bowling ball travelling at 3 m/s? (round to 3 decimal places as needed)
  1. Two oranges have the same momentum. Orange A has mass 0.2 kg and velocity 5 m/s. Orange B has a velocity of 7 m/s. What is Orange B’s mass? (round to 3 decimal places as needed)
  1. Which of the following has the greatest velocity?
  2. A .01 kg bullet with .05 J of kinetic energy
  3. A 7 kg bowling ball with 40 J of kinetic energy
  4. A 62 kg human with 100 J of kinetic energy
  5. A 1500 kg car with 10000 J of kinetic energy
  1. A 20 kg wagon at rest on the top of a hill has 50 J of potential energy. What is its velocity when it reaches the bottom of the hill? (round to 3 decimal places as needed)
  1. A wheel of cheese has mass m, velocity v, and kinetic energy KE. If the velocity is changed to 2v, what is the new kinetic energy?
  2. 0.5KE
  3. 2KE
  4. 4KE
  5. 16KE
  1. Hovercraft have a low “footprint pressure” (the pressure exerted on the ground). What can it be most closely compared to?
  2. An adult woman.
  3. A young horse.
  4. A bird on one leg.
  5. A child on snowshoes.
  1. Who is credited with the invention of the modern hovercraft?
  2. Sir Christopher Cockerell
  3. Sir John Isaac Thornycroft
  4. Orville Wright
  1. The idea of the hovercraft was first demonstrated with:
  2. A Coke bottle, a pillowcase, and a vacuum
  3. A coffee tin, a KiteKat cat food tin, and a hairdryer
  4. A FunnFish fish food can, a walnut can, and a straw
  5. A fork, a McDonald’s wrapper, and a pair of human lungs (blowing)
  1. The advantages of an air-cushioned vehicle in water include:
  2. Reducing resistance due to the water’s density
  3. Improving the lift-to-drag ratio
  4. Increased efficiency at all speeds
  5. A & B only
  6. A, B, & C
  1. Which is not an application for air-cushioned vehicles?
  2. Disaster relief
  3. Coastguard, military, and navy
  4. Non-land-based sea operations
  5. Racing
  1. Which of the following statements about hovercraft engines is incorrect?
  2. Typically, one engine may drive the impeller and others provide thrust.
  3. A lone engine is not powerful enough to provide both lift and thrust.
  4. Hovercraft are more fuel-efficient than other modes of transportation.
  5. The first passenger-carrying hovercraft was powered by two turboprop engines.

For questions 24-30, write the letter of the term from the word bank that matches the definition.

A. NRDC
B. Griffon 2000TD
C. Charles Joseph Fletcher
D. SR.N1 / E. John Isaac Thornycroft
F. Air-cushion pallets
G. Tuuli
  1. The first full-sized, functional hovercraft. ______
  1. This hovercraft was built for the Finnish Navy. ______
  1. This British government body was instrumental in the development of the hovercraft. ______
  1. This American inventor developed the Glidemobile, which is arguably the first hovercraft. ______
  1. These are used in the U.S. and Britain to carry heavy loads in factories. ______
  1. This is a lightweight hovercraft built in the U.K. for military and rescue operations. ______
  1. This British shipbuilder helped develop the hydrofoil. ______

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