17.4.2. Aerodynamics in Sports

Try these first

1. 1.

   Define drag force in your own words.

   Hint

   Think about why objects slow down in water or air.

2. 2.

   What is lift force?

   Hint

   Consider how airplane wings help them rise.

3. 3.

   What does the drag coefficient (Cd) represent?

   • The strength of lift
   • The resistance to motion
   • The speed of the fluid

   Hint

   Remember, Cd is about opposing motion.

4. 4.

   True or False: Lift acts parallel to the flow of air or water.

   • True
   • False

   Hint

   Think about how airplanes take off!

5. 5.

   You are conducting a wind tunnel test on a new bicycle design. The frontal area is 0.5 m², the drag coefficient is calculated to be 0.3, and the air density is 1.2 kg/m³. If the bicycle travels at 15 m/s, calculate the drag force experienced.

   Hint

   Make sure to substitute all known values accurately.

6. 6.

   A tennis player hits a ball of mass 0.058 kg with a diameter of 0.068 m at a spin rate of 3000 RPM. Calculate the lift force if the lift coefficient is 0.8 and the speed of the ball during play is 20 m/s. Will the ball rise or fall if the weight is 0.57 N?

   Hint

   Calculate the frontal area first, then substitute into the lift formula.