5. Figure shows a hypothetical（假设的） speed distribution for a sample of N gas particles (note that P(v)=0 for v>2v0). (a) Express a in terms of N and v0. (b) How many of the particles have speeds between 1.5v0 and 2.0v0? (c) Express the average speed of the particles in terms of v0. (d) Find vrms.
V0
2V0
a P(v)
6. One mole of an ideal monatomic（单原子的） gas is taken through the cycle shown in figure. Assume that p=2p0, V=2V0, p0=1.01*105Pa, and V0=0.0225m3. Calculate (a) the work done during the cycle, (b) the energy added as heat during stroke abc, and (c) the efficiency of the cycle. (d) What is the efficiency of a. Carnot engine operating between the highest and lowest temperatures that occur in the cycle? How does this compare to the efficiency calculated in (c)?
b c V, p Pressure a V0, p0 Volume
d Physcis（A）Answer
一．Fill in the blanks
1. -130km/h; 2.2m/s2; 2.2m/ s2 2.
m1T(m1?m2)TT; ;
m1?m2?m3m1?m2?m3m1?m2?m33. 8.74N; 37.9N; 6.45m/s 4. 184J; -184J; -184J
5. 5md2+8/3Md2; (5/2m+4/3M)d2ω2 6. 267rev/min; 2/3
7. 6.4m3; 5.4m/s 9.8*104Pa
8. 3.27mm; 8.71cm, 2.31s, 0.433Hz; 3.77cm/s; 1.92mm 9. 22atm
10. 65%; 1855J; 655J; 2.18J/K, -2.18J/K 二．Problems 1. 略 2．25cm
3. 6.00cm/s2; 4.87N; 4.54N; 1.20rad/s2; 0.0138kgm2 4. 2/3v0; N/3; 122v0; 1.31v0 5. 略
6． 2270J; 14800J; 15.4%; 75.0%