Question

Please explain why the correct answer is correct, and why the others can't be.

1. Why do astronauts on the International Space Station float, apparently weightless, rather than stand on the floor? (The space station is about 400km above the surface of the Earth) a. There is no gravity in space b. The gravitational field is virtually zero c. The astronauts have no mass in space d. The astronauts and space station are both in freefall e. The gravitational force of the Earth and Moon cancel at the location of the space station 2. Arigid, airtight submarine is loaded up 10 tons of cargo. How does the buoyant force on the submarine compare before to after it is loaded up, assuming it is completely submerged in water in both scenarios? a The buoyant force on the submarine is larger after it is loaded b. The buoyant force is the same in both scenarios c. The buoyant force on the submarine is larger before it is loaded d. It depends on the density of cargo e. It depends on the average density of the submarine 3. Blood flows through an artery with a partial blockage, which narrows the diameter of the blood vessel for a small segment of the total length. How does the pressure in the narrow portion of the blood vessel compare to the pressure just before the partial blockage? Assume that frictional effects have a negligible impact on the situation a. The pressure is higher in the narrow portion b. The pressure is the same in the narrow portion as before it c. The pressure is lower in the narrow portion d. It depends on the person's blood pressure measurements e. It depends on the strength of the person's heart

Answer 1

In Internasional Space station frame, gravitational force and centrifugal force due to revolusion, net force is zero mu? r< GMm so (6) The gravitational field is virtually Zero. submarine FT Buoyancy force = sug sa density of water, va volone of submarine If we loay Corgo, then volume of submarine does not change → le. FB = sug also constant. (6) Buoyancy force is some in - both scenarios.

7A Pi Glot (P2) By confutinuity equation AV = A₂V V₂ = Air v> 7 I we know Pa IPV ² so P₂ > Pi (9) The pressure is higher Portion. in the namow