Earphone definition, a sound receiver that fits in or over the ear, as of a radio or telephone. See more.
Answer Wiki. If a rocket went straight up, it would either continue in that direction and leave Earth, or it would fall back down, depending on its velocity. Most rockets intend to enter orbit, which is an elliptical trajectory, and it's much more efficient to arc into this trajectory than to go straight up and then accelerate laterally.
In a nutshell, a rocket must curve its trajectory post-launch, if it wants to enter the Earthâs orbit. If it didnât do that and continued to go straight up, it would eventually reach a point where its fuel would run out and, most likely, it would end up plummeting back to Earth like a stone. 1  Human Space Flight â NASA. 2  NASA SpacePlace. 3  Wikipedia. 4  NASA â Space Flight Systems.