PLEASE HELP Which list gives key events regarding the exploration of space in the correct order, beginning with the earliest?(1 point) first humans on the moon, first lander on Mars, first space shuttle flight

first space shuttle flight, Hubble Space telescope launch, last humans on the moon

first humans in space, first space shuttle flights, first humans on the moon

first humans on the Moon, first humans on Mars, launching of the International Space Station

The answer is d) by requesting advice on science internet sites

stands for electromotive force and it is measured in volts. despite its name, it is not actually the force in the sense of being a "pushing" or "pulling" (not measured in newtons).an equation that relates emf,  ℰ,  to a battery's terminal voltage, v, current, i, and internal resistance, r, is    ℰ = v + irin this case, the emf can be interpreted as a voltage—a difference in electric potential.i would not say that it would be considered an energy. if emf can be defined as the energy/work per a unit charge from a battery or other electric source, then it is not strictly energy.

The answer is 4f======since electrostatic force is given by    we let f be the electrostatic force when  r = 1 m    if we let  denote the electrostatic force when the distance is decreased so that r = 0.5m, then    we established earlier that f = kq₁q₂. therefore    the force will now be 4f.

Ray 2 should cross through the focal point on the right side of the lens