An object is dropped from rest from a height 5.6 × 106 m above the surface of the earth. if there is no air resistance, what is its speed when it strikes the earth? the acceleration of gravity is 9.81 m/s 2 and the radius of the earth is 6.37 × 106 m. answer in units of km/s.

If a substance is in the gas phase, which of qualities of the gas will stay constant? a: volume b: mass c: shape d: position of particles

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •  

Although longitudinal waves can travel through all media types what is the disadvantage of this type of wave transmission? a) he efficiency of he wave transmission is greatly diminished as the media becomes less dense b) the oscillation of one set of particles has a huge impact on neighboring particles c) particles become too close together as they bump into each other making it more likely to hit other particles down the line