WSI - Water Safety Instructor Hydrodynamics and Basic Skills Questions and Answers

Question 1

A swimmer's legs tend to sink, causing an increase in drag. This is primarily due to the relationship between which two hydrodynamic principles?

Accepted Answer

Center of Buoyancy and Center of Gravity

Answer

Propulsion and Form Drag

Answer

Wave Drag and Friction

Answer

Bernoulli's Principle and Lift

Question 2

A Water Safety Instructor is teaching a student the importance of a streamlined push-off from the wall. Which type of drag is most significantly reduced by maintaining a tight, streamlined position during a glide?

Accepted Answer

Form Drag

Answer

Wave Drag

Answer

Frictional Drag

Answer

Propulsive Drag

Question 3

Which of the following best describes the application of Newton's Third Law of Motion to swimming?

Accepted Answer

As a swimmer's hands and arms push the water backward, the water pushes the swimmer forward.

Answer

A swimmer will remain gliding at a constant speed unless slowed by the water's resistance.

Answer

The greater the force a swimmer applies to the water, the faster they will accelerate, assuming their mass is constant.

Answer

A swimmer with more muscle mass will require more force to achieve the same acceleration as a smaller swimmer.

Question 4

During a lesson on treading water, a student is struggling using the flutter kick and is tiring quickly. Which of the following kicks would be most effective and efficient for the student to maintain a vertical position?

Accepted Answer

Rotary (Eggbeater) Kick

Answer

Dolphin Kick

Answer

Scissor Kick

Answer

Inverted Frog Kick

Question 5

A swimmer is performing the front crawl with their head lifted too high. What is the most likely hydrodynamic consequence of this error?

Accepted Answer

It causes the hips and legs to drop, increasing form drag.

Answer

It generates greater propulsive lift.

Answer

It decreases wave drag around the head.

Answer

It improves the body's center of buoyancy.

Question 6

According to Archimedes' principle, the upward buoyant force that is exerted on a body immersed in water is equal to the:

Accepted Answer

Weight of the water the body displaces.

Answer

Mass of the body.

Answer

Volume of the water.

Answer

Density of the body.