# Density temperature relationship of water

### Density of Water - The Physics Factbook

The density of a liquid will change with temperature and pressure. The density of water versus temperature and pressure is indicated below: Water density vs. Feb 28, Mass, Specific Gravity or density, of water at various temperatures degree C. Water has a higher density in the liquid state than the solid, so ice cubes float. Within a particular phase, how does the density depend on temperature?.

While holding the card against the jar opening, carefully turn the jar upside down. With the card still in place, position the jar of hot water directly over the jar of cold water so that the tops line up exactly. Slowly and carefully remove the card so that the hot water jar sits directly on top of the cold water jar. Expected results Although removing the card may result in a little mixing or spilling, the hot yellow water will remain in the top jar and the cold blue water will remain in the bottom jar.

## Explanation of the Density Anomalies of Water (D1-D22)

Why do you think the hot water stayed on top of the cold water? Students should realize that there is a density difference between hot and cold water. Hot water is less dense so it floats on the denser cold water. Ask students to make a prediction: What might happen if you placed the cold blue water on top of the hot yellow water and then removed the card?

Cold water on top Use the same procedure as above, but place the jar of cold water, upside down over the jar of hot water.

Expected results The cold blue water will immediately fall into the hot yellow water causing mixing. The water will quickly become green throughout.

Why do you think the hot and cold water mixed when the cold water was placed on top? When the cold water is placed on top, the colors mix because the cold water is more dense and sinks in the hot water. Give each student an activity sheet. Students will record their observations and answer questions about the activity on the activity sheet.

## Temperature Affects Density

The Explain It with Atoms and Molecules and Take It Further sections of the activity sheet will either be completed as a class, in groups, or individually depending on your instructions. Look at the teacher version of the activity sheet to find the questions and answers. He observed that the volume of water pushed out of a tub, or displaced, by an object was equal to the volume of the object.

The buoyant force of the water is equal to the weight of the water displaced. An object accelerates when the forces on that object are unequal. Although acceleration is commonly used to describe an object that is speeding up, the scientific definition of acceleration means changing speed. An accelerating object can be speeding up or slowing down.

An object will always move in the direction of the greater force. An object may accelerate downwards sink or upwards rise in a body of water. If all of the forces on an object are balanced, there is no acceleration. In this case, the object may not move—like a book sitting on a flat table—or the object may move at a constant speed—like a car traveling at a steady 80 kilometers per hour.

In the water, an object might remain still either at the surface or within the water column. Three cubes of the same size, but with different masses and thus different densities, are placed in three beakers of water Fig. Because the cubes are identical in volume, they displace the same amount of water.

### Density, Temperature, and Salinity | az-links.info

Buoyant force is represented in Fig. These arrows are the same length for each of the cubes, indicating that the strength of the buoyant force acting on each cube is the same.

Because the masses of the cubes are not equal, the gravitational force G acting on each cube is different. Gravitational force is represented in Fig. These arrows are different lengths for each cube, indicating that the amount of the gravitational force is different for each cube. The downward pointing arrow in Fig. The downward pointing arrow is the longest in Fig 2.