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Category: Heat and Theromdynamics

1-and-2-are-the-temperature-coefficients-of-the-two-resistors-R-1-and-R-2-at-any-temperature-T-0-0-C-Find-the-equivalent-resistance-if-both-R-1-and-R-2-are-connected-in-series-combinatio

Question Number 44298 by Necxx last updated on 26/Sep/18 $$\alpha_{\mathrm{1}} \:{and}\:\alpha_{\mathrm{2}} \:{are}\:{the}\:{temperature} \\ $$$${coefficients}\:{of}\:{the}\:{two}\:{resistors} \\ $$$${R}_{\mathrm{1}} \:{and}\:{R}_{\mathrm{2}} \:{at}\:{any}\:{temperature}\:{T}_{\mathrm{0}} \\ $$$$\mathrm{0}°{C}.{Find}\:{the}\:{equivalent}\:{resistance} \\ $$$${if}\:{both}\:{R}_{\mathrm{1}} \:{and}\:{R}_{\mathrm{2}\:} \:{are}\:{connected}\:{in} \\…

A-body-cools-from-90-C-to-40-C-in-2-minutes-at-a-temperature-20-C-of-the-surrounding-Calculate-the-temperature-of-the-body-after-another-5-minutes-

Question Number 42497 by Necxx last updated on 26/Aug/18 $${A}\:{body}\:{cools}\:{from}\:\mathrm{90}°{C}\:{to}\:\mathrm{40}°{C}\:{in} \\ $$$$\mathrm{2}\:{minutes}\:{at}\:{a}\:{temperature},\mathrm{20}°{C} \\ $$$${of}\:{the}\:{surrounding}.{Calculate}\:{the} \\ $$$${temperature}\:{of}\:{the}\:{body}\:{after} \\ $$$${another}\:\mathrm{5}\:{minutes}. \\ $$ Commented by Necxx last updated…

How-much-sweat-must-evaporate-from-the-surface-of-150kg-of-human-body-to-be-able-to-cool-the-human-by-2-C-assume-C-3-35J-g-K-for-human-and-L-2-5mJ-kg-for-water-at-body-temperature-

Question Number 42261 by Necxx last updated on 21/Aug/18 $${How}\:{much}\:{sweat}\:{must}\:{evaporate} \\ $$$${from}\:{the}\:{surface}\:{of}\:\mathrm{150}{kg}\:{of}\:{human} \\ $$$${body}\:{to}\:{be}\:{able}\:{to}\:{cool}\:{the}\:{human} \\ $$$${by}\:\mathrm{2}°{C}.\left({assume}\:{C}=\mathrm{3}.\mathrm{35}{J}/{g}/{K}\:{for}\right. \\ $$$${human}\:{and}\:{L}=\mathrm{2}.\mathrm{5}{mJ}/{kg}\:{for} \\ $$$$\left.{water}\:{at}\:{body}\:{temperature}\right) \\ $$ Commented by Necxx…

Heat-is-supplied-at-a-rate-of-500W-to-a-pressure-cooker-containing-water-and-fitted-with-a-safety-valve-Steam-escape-such-that-water-is-lost-at-12g-min-If-the-heat-is-supplied-at-900W-water-is-lost-

Question Number 42262 by Necxx last updated on 21/Aug/18 $${Heat}\:{is}\:{supplied}\:{at}\:{a}\:{rate}\:{of}\:\mathrm{500}{W} \\ $$$${to}\:{a}\:{pressure}\:{cooker}\:{containing} \\ $$$${water}\:{and}\:{fitted}\:{with}\:{a}\:{safety}\: \\ $$$${valve}.{Steam}\:{escape}\:{such}\:{that}\: \\ $$$${water}\:{is}\:{lost}\:{at}\:\mathrm{12}{g}/{min}.{If}\:{the} \\ $$$${heat}\:{is}\:{supplied}\:{at}\:\mathrm{900}{W},{water}\:{is} \\ $$$${lost}\:{at}\:\mathrm{20}{g}/{min}.{Calculate}\:{the} \\ $$$${specific}\:{latent}\:{heat}\:{of}\:{steam}. \\…

Determine-the-total-translational-energy-of-two-litres-of-oxygen-gas-held-at-a-temperature-of-0-C-and-pressure-of-one-atmosphere-

Question Number 42131 by Necxx last updated on 18/Aug/18 $${Determine}\:{the}\:{total}\:{translational} \\ $$$${energy}\:{of}\:{two}\:{litres}\:{of}\:{oxygen}\:{gas} \\ $$$${held}\:{at}\:{a}\:{temperature}\:{of}\:\mathrm{0}°{C}\:{and}\: \\ $$$${pressure}\:{of}\:{one}\:{atmosphere}. \\ $$$$ \\ $$ Commented by Necxx last updated…

Calculate-the-density-of-1-mole-of-oxygen-at-a-pressure-of-4-10-4-Nm-2-and-temperature-of-273-2K-

Question Number 42128 by Necxx last updated on 18/Aug/18 $${Calculate}\:{the}\:\:{density}\:{of}\:\mathrm{1}\:{mole}\:{of} \\ $$$${oxygen}\:{at}\:{a}\:{pressure}\:{of}\:\mathrm{4}×\mathrm{10}^{\mathrm{4}} {Nm}^{−\mathrm{2}} \\ $$$${and}\:{temperature}\:{of}\:\mathrm{273}.\mathrm{2}{K}. \\ $$ Commented by Necxx last updated on 18/Aug/18 $${please}\:{check}\:{this}\:{approach}…

If-a-petrol-tank-costs-2000-00-to-fill-it-up-at-10-C-how-much-extra-must-I-pay-to-fill-up-the-tank-at-50-C-if-the-petrol-costs-50-00-per-litre-and-its-cubic-expansivity-is-9-5-10-4-K-1-

Question Number 42125 by Necxx last updated on 18/Aug/18 $${If}\:{a}\:{petrol}\:{tank}\:{costs}\:\sigma\mathrm{2000}.\mathrm{00}\:{to} \\ $$$${fill}\:{it}\:{up}\:{at}\:\mathrm{10}°{C},{how}\:{much}\:{extra} \\ $$$${must}\:{I}\:{pay}\:{to}\:{fill}\:{up}\:{the}\:{tank}\:{at}\:\mathrm{50}°{C} \\ $$$${if}\:{the}\:{petrol}\:{costs}\:\sigma\mathrm{50}.\mathrm{00}\:{per}\:{litre} \\ $$$${and}\:{its}\:{cubic}\:{expansivity}\:{is} \\ $$$$\mathrm{9}.\mathrm{5}×\mathrm{10}^{−\mathrm{4}} {K}^{−\mathrm{1}} ? \\ $$ Commented…

The-length-of-mercury-column-in-a-mercury-in-glass-thermometer-is-4cm-at-triple-point-What-is-the-length-of-the-column-when-the-scale-indicates-temperature-of-560K-

Question Number 41888 by Necxx last updated on 14/Aug/18 $${The}\:{length}\:{of}\:{mercury}\:{column}\:{in} \\ $$$${a}\:{mercury}-{in}-{glass}\:{thermometer} \\ $$$${is}\:\mathrm{4}{cm}\:{at}\:{triple}\:{point}.{What}\:{is}\:{the} \\ $$$${length}\:{of}\:{the}\:{column}\:{when}\:{the} \\ $$$${scale}\:{indicates}\:{temperature}\:{of} \\ $$$$\mathrm{560}{K}. \\ $$ Commented by Necxx…