Answer Happy

3) Astronomers at Caltech have used mathematical modeling of Pluto and Neptune's orbits to calculate the location of Planet X, the hypothetical ninth planet in the Solar System. (Pluto is not a Planet!) Unfortunately it is so far away from the Sun that it cannot be seen by any of our current telescopes, so NASA has Jorge (an Electrical Engineer at JPL) design an ion propulsion system for the 425 kg spacecraft that will be sent to find it. If Jorge's propulsion system accelerates singly ionized Argon through a 35 kV potential, and the propulsion is fired when the spacecraft is at rest, what will be the spacecraft's speed (in km/s) after it expels all of its 20 kg supply of Argon fuel?
1) Fiyouneh gets accepted to a Medical School in Idaho, and when she arrives she realizes that no matter where she goes throughout the entire state) she cannot find a good signal. To fix this problem, Fiyouneh orders a 2 m long antenna on Amazon, and attaches it to her iPhone. If Fiyounch's antenna carries a 900 uC charge, what will be the force (magnitude and direction) on a 5 C that is 30 cm (0.3 m) away from its center? [You must use the Electric field to receive full credit.)