Estimate the kinetic energy necessary for a projectile with mass m can "escape" from the surface of a planet if it is launched vertically upward. Express your estimation in terms of g which is the acceleration due to gravity at the planet's surface and rp which is the planet's radius. Ignore air resistance.

24 would be the answer

Which of the following is an example of an opposing signal? no examplthates given.   i would say, that traffic lights in a city at major intersections direct the flow of traffic in opposite directions so would be an example.also, stop signs on either side of the same street would be an example. at a train crossing, the light for allowing car traffic in opposite directions or not would be another example.