Question

a gas powered model airplane has a mass of 2.50 kilograms. A student exerts a force on a cord to keep the airplane flying around her at a constant speed of 18.0 meters per seond in a horizontal, circular path with a radius of 25.0 meters. what is the magnitude of the centripetal force exerted on the air plane to keep it moving in this circular path

Answer 1

The first thing to do in this case is a free-body diagram in the radial direction.From the free body diagram you get that
 Fc = m * ar
 where
 Fc: Centripetal force
 m: mass
 ar: radial acceleration
 By definition
 ar: v ^ 2 / r
 where
 v: speed
 r: radio
 Substituting the values
 Fc = m * (v ^ 2 / r)
 Fc = (2.50 * ((18 ^ 2 / (25)) = 32.4N
 answer
 the magnitude of the centripetal force exerted on the air plane to keep it moving in this circular path is 32.4N