Question

A Ping-Pong ball, which would ordinarily float, is held submerged in a bucket of water by a string attached to the bucket's bottom.

(a) Salt is now added to the water in the bucket, increasing the density of the liquid. What happens to the tension in the string?

A. The tension does not change.

B. The tension increases.

C. The tension decreases.

Answer 1

Adding salt increases the water's density, resulting in a greater buoyant force on the Ping-Pong ball, therefore decreasing the tension in the string that holds the ball submerged.

Step-by-step explanation:

When salt is added to the water in the bucket, increasing the liquid's density, the buoyant force on the Ping-Pong ball increases as well. Since a Ping-Pong ball ordinarily floats, the increased buoyant force acting on it as the water becomes denser means that it will experience a greater tendency to float. Consequently, the tension in the string holding it down will decrease because the string must exert less force to keep the ball submerged against the increased buoyant force.

When salt is added to the water in the bucket, it increases the density of the liquid. This increase in density makes the water more buoyant, exerting a greater upward force on the Ping-Pong ball. As a result, the tension in the string holding the ball submerged in the water decreases.