Find the value of aerodynamic constant C for this dimpled sphere.

[Sneakatone]

A falling golf ball (mass 45 g, radius 20.0mm) reaches high terminal speed of 42 m/s. what is the value of the aerodynamic constant C for this dimpled sphere?

I tried using mv^2/r -> (0.45 kg)*(42 m/s)/0.2m=94.5 but Its not correct. I don't understand what they mean by constant C.

 

[SteamKing]

Well, the golf ball is undergoing linear motion. Your formula is for the centripetal force on an object in circular motion. What you need is a formula for terminal speed of an object which is falling.

 

[Sneakatone]

V=sqrt(2mg/pAC)

 

[Sneakatone]

if this is the right equation should the units of v=km/h and r=m?
in other words what should the units be?

 

[haruspex]

if this is the right equation should the units of v=km/h and r=m?
in other words what should the units be?

Anything you like as long as you are consistent. Put everything into MKS units and you should be safe.

 

[Sneakatone]

would you recommend I convert to km since p is km?

 

[haruspex]

would you recommend I convert to km since p is km?

Isn't p (rho) the density? That would be kg/m³ in MKS.