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The-standard-enthalpy-of-formation-of-gaseous-H-2-O-at-298-K-is-241-82-kJ-mol-1-Estimate-its-value-of-100-C-given-the-following-values-of-the-molar-heat-capacities-at-constant-pressure-H-2-O-g-

Question Number 23135 by Tinkutara last updated on 26/Oct/17 ThestandardenthalpyofformationofgaseousH2Oat298Kis241.82kJmol1.Estimateitsvalueof100°Cgiventhefollowingvaluesofthemolarheatcapacitiesatconstantpressure:$$\mathrm{H}_{\mathrm{2}} \mathrm{O}\left(\mathrm{g}\right)\::\:\mathrm{35}.\mathrm{58}\:\mathrm{JK}^{−\mathrm{1}} \:\mathrm{mol}^{−\mathrm{1}} ,\:\mathrm{H}_{\mathrm{2}}…

A-baloon-filled-with-helium-rises-against-gravity-increasing-its-potential-energy-The-speed-of-the-baloon-also-increases-as-it-rises-How-do-you-reconcile-this-with-the-law-of-conservation-of-mechani

Question Number 23130 by Tinkutara last updated on 26/Oct/17 Abaloonfilledwithheliumrisesagainstgravityincreasingitspotentialenergy.Thespeedofthebaloonalsoincreasesasitrises.Howdoyoureconcilethiswiththelawofconservationofmechanicalenergy?Youcanneglectviscousdragofairandassumethat$$\mathrm{density}\:\mathrm{of}\:\mathrm{air}\:\mathrm{is}\:\mathrm{constant}. \

A-rocket-accelerates-straight-up-by-ejecting-gas-downwards-In-a-small-time-interval-t-it-ejects-a-gas-of-mass-m-at-a-relative-speed-u-Calculate-KE-of-the-entire-system-at-t-t-and-t-and-show-th

Question Number 23066 by Tinkutara last updated on 25/Oct/17 Arocketacceleratesstraightupbyejectinggasdownwards.InasmalltimeintervalΔt,itejectsagasofmassΔmatarelativespeedu.CalculateKEoftheentiresystematt+Δtandtandshowthatthedevicethatejectsgasdoeswork=(12)Δmu2inthistime$$\mathrm{interval}\:\left(\mathrm{neglect}\:\mathrm{gravity}\right).…

show-that-the-variance-2-of-a-set-of-observations-x-1-x-2-x-n-with-mean-x-can-be-expressed-in-the-form-2-i-1-n-x-i-2-n-x-2-

Question Number 88592 by Rio Michael last updated on 11/Apr/20 showthatthevarianceδ2ofasetofobservationsx1,x2,xnwithmean$$\overset{\_} {{x}}\:\mathrm{can}\:\mathrm{be}\:\mathrm{expressed}\:\mathrm{in}\:\mathrm{the}\:\mathrm{form}\:\:\delta^{\mathrm{2}} \:=\:\frac{\underset{{i}=\mathrm{1}} {\overset{{n}} {\sum}}{x}_{{i}} ^{\mathrm{2}} }{{n}}\:−\:\bar {{x}}\:^{\mathrm{2}\:} \