Cold air rises because it is denser than water, is this true?​

Aboat that travels with constant speed of 6.10 m/s in still water is to go directly across a river. the current in the river flows at 1.95 m/s. (a) at what angle must the boat be steered?

The sun generates both mechanical and electromagnetic waves. which statement about those wave is true?

Which of the choices below is one of the primary gases found in the atmosphere? a. helium b. carbon dioxide c. nitrogen d. argon