Any machine which moves an object produces work. true or false

Aroller coaster car moving at a velocity of 30 meters/second has a momentum of 2.5 x 10^4 kilogram meters/second. what is its mass?

The “death throes” of stars are amongst the most complex phenomena in all of astronomy, and the “corpses” of stars amongst the most energetic and exotic objects in existence. beginning at the end of the core helium fusion stage in a star’s life, describe in detail the post-main sequence development of both (a) a 1.0 solar mass star, and (b) a 25.0 solar mass star. in what significant ways do they differ? what role does each of these types of stars play in the "star-gas-star" cycle and the evolution of chemical elements in our galaxy?

The air that we breath is made mostly of which gaseous molecule