A small ball of mass m = 5 kg is suspended from
a string of length L = 5 m. The ball revolves
with constant speed v in a horizontal circle of
radius r = 2 m. Find an expression for v and a.

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?

What can you increase the strength of an electromagnet by

Which of the following forces require physical contact? tension air resistance friction magnetic force applied force