In which of the following situations is there observational evidence for significant interaction between two objects? how can you tell?

1 .a communications satellite orbits the earth.
2. a ball bounces off a wall with no change in speed.
3. a space probe travels at constant speed toward a distant star.
4. a baseball that was hit by a batter flies toward the outfield.
5. a charged particle leaves a curving track in a particle detector.

Suppose that two tanks, 1 and 2, each with a large opening at the top, contain different liquids. a small hole is made in the side of each tank at the same depth 1.57 m below the liquid surface, but the hole in tank 2 has 2.49 times the cross-sectional area of the hole in tank 1. (a) what is the ratio ρ1/ρ2 of the densities of the liquids if the mass flow rate is the same for the two holes? (b) what is the ratio rv1/rv2 of the volume flow rates from the two tanks? (c) at one instant, the liquid in tank 1 is 14.9 cm above the hole. if the tanks are to have equal volume flow rates, what height above the hole must the liquid in tank 2 be just then?

Blank liquids and gases exert a buoyant force on objects placed in them

Select the correct answer. what does the process of natural selection involve?