A 0.4 kg bouncy ball is dropped from a 11 meter buldingit bounces up to a height of 9.5 meters. How much energy was lost in the system?

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

Metals are good conductors of electricity because they

It's time for santa to deliver his presents. assuming he delivers presents all over the world, he has to travel about 75,000,000 miles. if he travels east to west, he can use the time zones to make christmas day last 31 hours. what speed, in miles per hour, must santa fly to get all of his presents delivered?