Water is in the big beaker in the figure on the left. Scale 1 reads 87 Newtons, scale 2 reads 544 newtons, and scale 3 reads 0 newtons. The hanging block has a density of 15 x 10^3 kg/m^3.

What does scale 1 read after the block is fully lowered into the beaker of water?
Scale 1 reads:

What is the new reading on scale 2?
Scale 2 reads:

The experiment is repeated with the valve opened. What is the new reading on scale 3?
Scale 3 reads:

With the valve opened, what is the new reading on scale 2?
Scale 2 reads:

To answer these questions, we need to understand the concept of buoyancy and how it affects the scale readings.

1. What does scale 1 read after the block is fully lowered into the beaker of water?
Scale 1 measures the apparent weight of the block when immersed in water. When an object is submerged in a fluid, it experiences an upward force called buoyant force, which counteracts the force of gravity. The buoyant force is equal to the weight of the fluid displaced by the object. The scale 1 reading will be reduced by the buoyant force acting on the block. To calculate it, we need to determine the volume of the block, multiply it by the density of water, and then by acceleration due to gravity (9.8 m/s^2). Subtracting this buoyant force from the initial reading on scale 1 will give us the new reading.

2. What is the new reading on scale 2?
Scale 2 measures the total weight acting on it, including the weight of the block and the weight of the water displaced by the block. When the block is fully lowered into the water, it displaces a volume of water equal to its own volume. The weight of this displaced water will be added to the initial reading on scale 2.

3. The experiment is repeated with the valve opened. What is the new reading on scale 3?
Scale 3 measures the tension in the string supporting the block. In the initial setup, the block is not connected to scale 3, so the reading is zero. However, after opening the valve, water can flow inside the hollow block, affecting the tension in the string. The weight of the water that enters the block will increase the tension in the string and, therefore, the reading on scale 3.

4. With the valve opened, what is the new reading on scale 2?
Opening the valve allows water to flow into the hollow block, which changes the amount of water displaced by the block and, subsequently, its weight. This change in weight will affect the reading on scale 2.

To calculate the specific values for these scale readings, I would need additional information such as the dimensions of the beaker, the dimensions of the block, and the length of the string supporting the block.