Define the term momentum. Name the device used to measure atmospheric pressure. State two properties of an ideal gas. What is the principle behind the construction of a simple hydrometer?

Here are the solutions to the questions. 1. a) Momentum is defined as the product of an object's mass and its velocity. It is a vector quantity, and its direction is the same as the velocity of the object. p = mv b) The device used to measure atmospheric pressure is a barometer. 2. a) Two properties of an ideal gas are: • The volume occupied by the gas molecules themselves is negligible compared to the total volume of the gas. • There are no intermolecular forces of attraction or repulsion between the gas molecules. (Alternatively: Collisions between gas molecules and the container walls are perfectly elastic.) b) The principle behind the construction of a simple hydrometer is Archimedes' principle (or the principle of floatation). This principle states that a floating object displaces a weight of fluid equal to its own weight. A hydrometer sinks deeper in less dense liquids and floats higher in more dense liquids. Last free one today — make it count tomorrow, or type /upgrade for unlimited.