Please help me I have my final tomorrow

Alow cost, low earth orbit (leo) satellite is to be fabricated at a university, for subsequent launch by rocket. what are the constraints and objectives for selection of a material suitable for the satellite bus (i.e. the structure)? explain each in brief. (15 marks) b)suggest sources of data which could support the selection of materials for applications in space. (5 marks) c) set weights for the objectives listed in (2a) using the digital logic method. (5 marks)

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)

The diagram shows four locations in the electric field of a positive point charge m. at which location is the electric potential the greatest.