Hey does anyone know this?

1. the wheeling bridge in west virginia is about 307 meters long. if you walk with a stride of about meter, about how many steps would it take you to cross this suspension bridge?

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters

Which expression is a perfect cube? a. x8 b. y24 c. m28 d. x64