A wooden ball is tied to the bottom of a swimming pool by a string.What is the tension in the string if the ball's diameter is 0.15 m and its mass is 144 g? The water in the pool is fresh water,1000 kg/m³ density. A) 0.35 N B) 12.7 N C) 14.1 N D) 1.78 N

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Quizplus · Accepted Answer

The tension in the string is equal to the weight of the ball in water. The weight of the ball in water is equal to the weight of the ball in air minus the buoyant force. The buoyant force is equal to the weight of the water displaced by the ball. The volume of the ball is equal to 4/3 * pi * (0.15 m / 2)^3 = 0.00177 m^3. The weight of the water displaced by the ball is equal to 0.00177 m^3 * 1000 kg/m^3 * 9.81 m/s^2 = 17.3 N. The weight of the ball in air is equal to 144 g * 9.81 m/s^2 = 1.41 N. Therefore, the tension in the string is equal to 1.41 N - 17.3 N = 0.35 N.

A Wooden Ball Is Tied to the Bottom of a Swimming