Fluid Mechanics

What is the primary factor determining the drag force on an object moving through air?

• The object's weight

• The object's velocity

• The back area

• The air temperature

• The object's colour

How does a headwind affect the motion of a moving object?

• Decreases the relative velocity

• Reduces air density

• Increases the relative velocity and drag force

• Cancels out all forces

Which factor does NOT directly influence the drag force on an object?

• Air density

• Object's velocity

• Object's Mass

• Drag Coefficient

A spinning object curves in flight due to which effect?

• Gravitational pull

• Magnus Effect

• Air density variation

• Drag force alone

What is the drag force on an object with a frontal area of 0.2 m², drag coefficient of 0.8, moving at 10 m/s in air with density 1.2 kg/m³?

• 9.6N

• 12N

• 19.2N

• 24N

Which adjustment would reduce air resistance for a moving vehicle?

• Increasing its speed

• Reducing its frontal area

• Increasing its drag coefficient

• Adding more weight

What happens to drag force if an object’s speed doubles?

• It doubles

• It quadruples

• It divides in two

• It remains constant

Why does a streamlined shape reduce air resistance?

• Increases frontal area

• Decreases the drag coefficient

• Increases air density

• Reduces the object’s speed

Which factor increases the relative velocity of an object moving against a wind?

• Wind speed in the same direction

• Wind speed in the opposite direction

• Reduced air density

• Increased object mass

How does increasing the spin rate of a ball affect its trajectory?

• Reduces the curve

• Increases drag but not the curve

• Slows the ball without curving it

• Increase the curve