How could this gravitational potential energy be transformed into kinetic energy?
A.
He could start the engine.
B.
He could release the brakes.
C.
He could push it up the hill.
D.
all of these

Which characteristics can be used to differentiate star systems? check all that apply.

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.

Is 9 correct? and can someone me with 10? it’s due tomorrow, you