A container of water is placed on a scale, and the scale reads 120. g. Now a 20.0g piece of copper (specific gravity = 8.90) is suspended from a thread and lowered into the water, not touching the bottom of the container. What will the scale now read?
A) 140 g
B) 122 g
C) 138 g
D) 112 g
E) 120 g

Question

Quizplus · Accepted Answer

The scale will read the original weight of the water plus the buoyant force, which is equal to the weight of the displaced water. The copper displaces 20 g / 8.90 = 2.25 g of water, so the scale reads 120 g + 2.25 g = 122.25 g, approximately 122 g.

A Container of Water Is Placed on a Scale, and the Scale