Question

A hollow ball with a diameter of 3.81 cm has an average density of 0.0842 g/cm3. What force must be applied to hold it stationary while it is completely submerged under water? (Enter the magnitude in N, and select the direction from the options given.)

Answer 1

Answer:

0.26

Explanation:

Given that :

Diameter of ball = 3.81 cm = 3.81/100 = 0.0381 m

Radius (r) = 0.0381 / 2 = 0.01905 m

Average density of ball (Db) = 0.0842 g/cm³ = (0.0842 / 1000)kg / 10^-6 = 0.0842/ 1000 * 10^6 = 84.2kg/m³

Density of water (Dw) = 1000kg/m³

Volume of hollow ball: (4/3) * pi * r³

V = (4/3) * π * 0.01905^3

V = 0.0000289583 m³

Required force = (Dw * V * g) - (Db * V * g)

= (1000 * 0.0000289583 * 9.8) - (84.2 * 0.0000289583 * 9.8)

= 0.259896109172

= 0.2598 N