Let a spacecraft in permanent orbit around the earth be used for delivering payloads from leo to geostationary (gso) orbit. before each flight from leo the spacecraft is refueled with propellant which it uses up in its round trip to gso and back. the outbound leg requires four times as much propellant as the inbound return leg. the delta-v for hohmann transfer from leo to gso is 4.22 km/s. the specific impulse of the propulsion system is 430 s. if the payload mass is to be 3500 kg, calculate the mass of the empty vehicle.

Thomas his older brothers, who own a junk yard, on the weekends to earn extra money. he likes to them push broken-down cars to the back of the junk yard because it makes him feel strong. last saturday, they pushed three cars with different weights, and he noticed he used different amounts of force for each one. the cars were the following weights: white car: 2,700 kg red car: 1,500 kg blue car: 2,100 kg think about how much force is needed to move each car. which correctly lists the cars in order from the most to least amount of force needed to move them? a) white, blue, red b) blue, red, white c) red, white, blue d) white, red, blue