On a safari, you are spear fishing while wading in a river. you observe a fish gliding by you. if your line of sight to the fish is 60.0° below the horizontal in air, and assuming the spear follows a straight line path through the air and water after it is released, determine the angle below the horizontal that you should aim your spear gun in order to catch dinner. assume the spear gun barrel is 2.00 m above the water surface, the fish is 1.70 m below the surface, and the spear travels in a straight line all the way to the fish ebook

Uranium has two naturally occurring isotopes. 238u has a natural abundance of 99.3% and 235u has an abundance of 0.7%. it is the rarer 235u that is needed for nuclear reactors. the isotopes are separated by forming uranium hexafluoride uf6, which is a gas, then allowing it to diffuse through a series of porous membranes. 235uf6 has a slightly larger rms speed than 238uf6 and diffuses slightly faster. many repetitions of this procedure gradually separate the two isotopes. what is the ratio of the rms speed of 235uf6 to that of 238uf6? express your answer to five significant figures.