A0.300 kg balloon is filled with helium until the volume of the balloon is 1.50m^3. the density of the contained helium is 0.178 kg/m^3, and the density of the surrounding air is 1.29 kg/m^3. what downward force must be applied to the balloon to prevent it from rising?

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?

It can take some of those large , industrial vehicles up to feet to stop when traveling only 60 mph, and therefore , you shoukd be mindful to not be jn the traffic right in front of them a. 100 feet b. 200 feet c. 335 feet d. 425 feet

An object moves from position +34m to the position -15m in 15 seconds. what is the total displacement? what is the total velocity?