Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

child playing in a swimming pool realizes that it is easy to push a small inflat

ID: 1837317 • Letter: C

Question

child playing in a swimming pool realizes that it is easy to push a small inflated ball under the surface of the water while a large ball requires a lot of force. The child happens to have a styrofoam ball (this way the shape of the ball will not distort when it is forced under the surface) which is being forced under the surface of the water. If the child needs to supply 581 N to totally submerge the ball, calculate the diameter of the ball. The density of water is rho_w = 1.000 times 10^3 kg/m^3, the density of styrofoam is rho_foam = 95.0 kg/m^3 and the acceleration due to gravity is g = 9.81 m/s^2.

Explanation / Answer

balancing forces on ball:

Fappl + mg - Fb =0

Fb = buoyant force = V* rho_water * g

581 + ( V * rho_foam * g ) - (V* rho_w * g) = 0

581 + (931.95V) - ( 9810V) = 0

V = 0.0654 m^3

V = 4 pi R^3 / 3

R = 0.25 m

d = 2R = 0.50 m .....Ans