Question1
A Carnot engine operates with an effectiveness of 24.0 percent as the temperature of its cold reservoir is 290 K. assume that the temperature of the hot reservoir remains the same, what must be the temperature of the cold reservoir in order to increase the efficiency to 29.0%?
Question2
A steel wire has the next properties:
Length = 5.00 m
Cross-sectional area = 0.040 cm^2
Young's modulus = 2.0 * 10^11 Pa
Shear modulus = 0.84 * 10^11 Pa
Proportional limit = 3.6 * 10^8 Pa
Breaking stress = 11.0 * 10^8 Pa
The wire is fastened at its upper end and hangs vertically.
A) How great a weight can be hung from wire without exceeding the proportional limit?
B) How much does the wire stretch under this load?
C) What is the highest weight that can be supported?