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Che111:Chapter7PracticeProblems
1. Thesimplestdefinitionof_energy_________isthatitisthecapacitytodowork.Work,
inthiscontext,maybedefinedaswhatisdonetomoveanobjectagainstsomesortof
___resistance___.
2. Thecapacitytodoworkresultingfromthe___motion__ofanobjectiscalledkinetic
energy,KE.
3. TheLawofConservationofEnergystatesthatenergycanbeneither_created__nor
___destroyed___,butitcanbe__transferred_fromonesystemtoanotherand
__change____fromoneformtoanother
4. Potentialenergy(PE)isa(n)__stored__formofenergyanobjectpossessebyvirtueof
its___position___.
5. Achangethatleadsto___heat___energybeingreleasedfromthesystemtothe
surroundingsiscalledexothermic.
6. Foreachofthefollowingchanges,describewhether
(1)kineticenergyisbeingconvertedintopotentialenergy,
(2)potentialenergyisbeingconvertedintokineticenergy,or
(3)kineticenergyistransferredfromoneobjecttoanother.
(Morethanoneofthesechangesmaybeoccurring.)
a) Acarinanoldwoodenrollercoasterisslowlydraggedupasteepinclinetothe
topofthefirstbigdrop.(1)
b) Afterthecarpassesthepeakofthefirsthill,itfallsdownthebacksideathigh
speed.(2)
c) Asitgoesdownthehill,thecarmakesthewholewoodenstructureshake.(3)
d) Bythetimethecarreachesthebottomofthefirstdrop,itismovingfastenough
togouptothetopofthenextsmallerhillonitsown.(1)
e) Windturnsthearmsofawindmill.(3)
f) Thewindmillpumpswaterfrombelowthegroundupintoastoragetankatthe
topofahill.(3),(1)
7. Classifyeachofthefollowingchangesasexothermicorendothermic.
a. Thenuclearreactionthattakesplaceinanuclearelectricalgeneratingplant.
exothermic
b. Cookinganegginboilingwater.
endothermic
c. Thebreakdownofplasticinthehotsun.
endothermic