Question

4. Two 3.5 kg blocks of lead are sus are initially not in contact. g. One is at 80°C, while the other is at 30°C. They a. If the two blocks are brought into contact, what is the final temperature of the rought into contact, what is the final temperature of the two blocks? How much heat is transferred in the process? You may assume no heat is lost to the environment. b. The two blocks are brought into contact by a 0.15 kg bar of copper of length 10 cm and an area of 1.6 cm. How long does it take for the system to reach its final temperature? c. What assumptions did you make in coming up with your time for part b)? (Hint: is the rate of heat flow constant over time?)

Answer 1

Answer Dayiwo 3.5 kg blodes of lead are suspened from are suspended Ceiling. 1 One is at soc. other is at 30°c They are initially not in contact. from the given data not plavo o od m= 3:5 legono solo mool 1. ; 12 = 30°C The final temparature of the two blocks, Aleiad less by one block; heat gain by deed block... . .. here we have .. mi CC9-14). - mac (24-1) here By substituting the values, 8.g (80.79)-375 (9f-30)

here wi here we got. 298110 7. By deviding 14285e. . The two blocks are brought into contact ci here we have Q : mc. 89 la 128 g/kq here we have 8.5X128 (55-80). here by multiplication. Here we got the angooses of heat transfer Qo'll, 2005,

nghs into b) the two blocks are brought into contacto I by a ben of copper of length 40 em and an area of 1.6 ent, I Here from the given, the rate heat I flow through the ball i heure do = KAL?) here k: 38% wimb. messleg .mq 23.5 kg m = oils leg A=1.6 m² art=10cm 201m. olen - 385x (80-30) x1,6x104 - - O'

here we got de = 30$ Alsec. reta u = 363.65 sec here we got to 363063 See time for the system to reach final temparature. the