Acustomer complains that the heater works sometimes, but sometimes only cold air comes out while driving. technician a says that the water pump is defective. technician b says that the cooling system could be low on coolant. which technician is correct?

After the near spacecraft passed mathilde, on several occasions rocket propellant was expelled to adjust the spacecraft's momentum in order to follow a path that would approach the asteroid eros, the final destination for the mission. after getting close to eros, further small adjustments made the momentum just right to give a circular orbit of radius 45 km (45 × 10^3 m) around the asteroid. so much propellant had been used that the final mass of the spacecraft while in circular orbit around eros was only 545 kg. the spacecraft took 1.04 days to make one complete circular orbit around eros. calculate what the mass of eros must be.

Idon’t quite understand this problem

Gordon is going for a run through the park, but it is cold outside. the low outside temperature could affect his personal safety.