A train blows its whistle as it moves rapidly towards a stationary observer. Which of the following best describes the sound of the whistle as heard by the observer in comparison to the sound as heard by a passenger on the train?

The freezing and boiling point of a substance changes as the air pressure around it changes. for example, at a lower air pressure (higher altitude) it is easier for water molecules to escape from liquid into the air. in a high altitude city such as denver, colorado compared to a sea-level city such as houston, texas, water

What is the relationship between the direction of motion of the balloon and the wind currents

Provides most of the energy used in the world today. question 4 options: wind fossil fuel moving water sunlight