PHYSICS 15A Lecture 25: Lecture 25

(a) calculate the carnot efficiency
(b) calculate the aborbed heat QH from the high temperaturereservoir
(c) calutlate the-liberated heat QC to the heat sink
(d) what is the total work done
(e) what is the volume contraction ratio of the gas during theisothermal compression at the lower temperature?

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Three charges are at the corners of an equilateral triangle withsides of length 0.500 m.

(a) What is the vector electric field at the position of charge QA= 4.00 ? due
to QB = -7.00 ? and QC = 3.00 ?? E =

(b) Use your answer to part (a) to determine the vector force on onQB

Two charges, Q_A = 5 μC and Q_B = -6 μC, arespaced 20 cm apart. Find the change in potential energy as a pointcharge Q_C = 4 μC moves from (1) the midpoint betweenQ_A and Q_B to (2) 5 cm to the left ofQ_A, directly opposite of Q_B.

a. 3J

b. 4J

c. 5J

d. 6J

e. 7J