Why do some scientists believe the exosphere should not be considered a part of the atmosphere? a. it has virtually no gases from the earth in it. b. the atmosphere already has numerous layers. c. without molecules, there is no ability to retain heat. d. many of the sun's ultraviolet rays reside in this layer.

Aquarterback pedals 3.3meters southward and then run 5.7meters northward. whats the distance ? and whats the displacement?

Oxygen and hydrogen gas are at the same temperature t.what is the ratio of kinetic energies of oxygen molecule and hydrogen molecule if oxygen is 16 times heavier than hydrogen.

Asolid cylinder and a cylindrical shell have the same mass, same radius, and turn on frictionless, horizontal axles. the cylindrical shell has light-weight spokes connecting the shell to the axle. a rope is wrapped around each cylinder and tied to blocks of equal masses that are held the same height above the ground. both blocks are released simultaneously. the ropes do not slip. which block hits the ground first? or is it a tie?