The rock sitting on the hill in the picture above. gravity should make the rock slide down the hill. what force is acting to balance gravity, keeping the rock in place?

The transfer of heat through the movement of a gas or liquid a. convection b. conduction c. radiation

Determine the age of a fossil if it had only one eighth of its original carbon-14 content remaining?

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.