Fluid Mechanics in Biomechanics

What must an object be in order to float in water?

• Heavier than the water it displaces

• The same density as the water it displaces

• Less dense than the water it displaces

• More dense than the water it displaces

What is the center of buoyancy?

• The center point of the mass below the water

• The point where the object touches the water

• The point where gravity acts

• The center point of the mass above the water

What happens if the buoyant force does not pass through the center of mass?

• The object will rotate

• The object will sink

• The object will float

• The object will remain stationary

What is fluid resistance also known as?

• Buoyancy

• Thrust

• Drag

• Lift

What are the two main sources of drag?

• Friction and lift

• Thrust and friction

• Pressure and lift

• Pressure and friction

What is pressure or form drag?

• The pressure difference at the front and rear of an object

• The friction between fluid particles

• The lift force acting on an object

• The thrust force acting on an object

Why do swimmers use swim caps and goggles?

• To increase buoyancy

• To increase drag

• To decrease pressure

• To reduce friction

What is the Magnus effect?

• The effect of buoyancy on a floating object

• The effect of gravity on a spinning object

• The use of spin on a ball to change its movement

• The use of drag to slow down an object

How does the Magnus effect influence a ball?

• It causes the ball to move in a straight line

• It causes the ball to curve through the air

• It makes the ball sink

• It makes the ball float

What material are modern surfboards made of?

• Plastic

• Polystyrene or polyurethane

• Metal

• Wood