A student uses a lever and fulcrum to lift a rock off the ground. Which option describes when potential energy is converted into kinetic energy during this process?

a. when the lever is wedged beneath the rock but before it has been lifted

b. when the student presses down on one side of the lever to cause it to move

c. when the rock rests on the ground without the lever

d. when the rock rests above the ground

Si una estrella no tiene paralaje medible, ¿qué puedes inferir?

Indicate whether the specified alkyl halides will form primarily substitution products, only elimination products, both substitution and elimination products, or no products when they react with sodium methoxide. 1-bromobutane 1-bromo-2-methylpropane 2-bromobutane 2-bromo-2-methylpropane

A100 kmol/h stream that is 97 mole% carbon tetrachloride (ccl4) and 3% carbon disulfide (cs2) is to be recovered from the bottom of a distillation column. the feed to the column is 16 mole% cs2 and 84% ccl4, and 2% of the ccl4 entering the column is contained in the overhead stream leaving the top of the column. calculate the mass and mole fractions of ccl4 in the overhead stream, and determine the molar flow rates of ccl4 and cs2 in the overhead and feed streams. 12. mw_ccla- 153.82; mw_cs2-76.14.