A train is accelerating at a rate of 2 m/s squared. if its initial speed of 20 m/s how long does it take the train to reach a speed of 80 m/s

Which of the following compounds does not contain molecules? question 2 options: co2 h2 nacl h2o

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.

What was bohr’s contribution to the planetary model