Question

The heating element of a coffeemaker operates at 120 V and carries a current of 5.50 A. Assuming the water absorbs all of the energy converted by the resistor, calculate how long it takes to heat 0.710 kg of water from room temperature (23.0°C) to the boiling point. min Need Help? Read It Master It -/10 Points] DETAILS SERCP11 17.2.P.005. A certain laboratory experiment requires an aluminum wire of length of 27.0 m and a resistance of 4.30 at 20.0°C. What diameter wire must be used? (The resistivity of aluminum at 20.0°C is 2.82 x 10-82.m.) mm Need Help? Read It –/10 Points] DETAILS SERCP11 17.4.P.020. A rectangular block of copper has sides of length 18 cm, 27 cm, and 42 cm. If the block is connected to a 6.4 V source across two of its opposite faces, find the following. (a) What is the maximum current the block can carry? (b) What is the minimum current the block can carry? Need Help? Read It Watch It [-/10 Points] DETAILS SERCP11 17.2.P.006. If 3.00 x 10-3 kg of gold is deposited on the negative electrode of an electrolytic cell in a period of 2.77 h, what is the current in the cell during that period? Assume the gold ions carry one elementary unit of positive charge. ma

Answer 1

Tir 28°C, If = 100e . 1) volitage, iw=120v Current, £25.50 A. mass of water, nro: 410 kg Room temperadine, Boiling temperature of water, amount of heat needed to to reach the boining demperature, og s mest, cr 4186 51 kg ka a86 slkgl. : 085 0.710 ng x 4186 slmy zyl1902 -23°c) së 228848.62 J . now Power Produced by the waffee maker, 66051s. Pore o 12o ry 5.50 A The & cp.t / (398: 74.)*5.8 mm mw energy => to P fra 228848-621 6 34 6:74 s 660 55 Its 5.8 mm 00 cergth of wire, e=127.0m, Resumine, R = 9:302 Resistivity of amminium at 202, P5 2.82x108 som are know for pe A E td area ross-section. Aro Pe = 1.7707810 2 rim 27 m R 2682 x10 82 9.802 4x1.7707810 otn 22:57 MW ind TÄ :) da LAA =4.758104 mr.o. 475 mm ( Diameter of the wire must had a 0.475 mm

I voltage ratar, Resistivity of copper, prolo22 x 1882.m 2 I We know fr PL = P = VA A were R2 N currert, fe resistorie Again, Anda NG of the bloue. No Volume E= VVO pa , Tatt now current will he meximum of Ls small. so, = 18 cm018 m Eo, volume of the block, Vos is cm x 27 cm x 42 cm 0.18m x 0.27 mg 0.42 mao.o. 3 0.020412m 6. 4NX 0.02.04 12 w3 3 2.34*10* A. 1. #2 *10*32 cm x (0-18 m) so, magmum current, the block can carry is @ Timex a 2.34X108 A ）. or mm, mum 6 ła current, his large. so, 25.0 42 m 6.90 0.020412 m3 43311X10 A. 114271862.mx (0.42 m) minimum current, the block con carry is, F4311 X 10 An (6) Emin

wrthins No 6.022x16 atons. free Armount of gold, w ma 1,100x10.Pry ing Aforrie mass of gold, Arc 1970 I mole of gold aroma 1979: 123 I mone of joid atom sumber of atom deposited is 23 3 g x 6.02.2010 197 g na ana A nr 9.170 56 x 10 here, & a 2.78 h (2-7 na(2-4**3 fon) sa 5-99725. e = 16x1013 enarge of election, 1r.17088184x18x1813 now current, he ) LA Ec it 93723 220-147A = 147mA current in the shell, 12 147 mA
the heat energy required to change the temperature from T1 to T2 is given by

Q=mc∆T = mc(T2-T1)

The resistance of the wire , $R=\frac{\rho l}{A}$