College Physics 2e

# Chapter 33

### Problems & Exercises

1.

$3 × 10 − 39 s 3 × 10 − 39 s$

3.

$1 . 99 × 10 − 16 m ( 0 . 2 fm ) 1 . 99 × 10 − 16 m ( 0 . 2 fm )$

4.

(a) $10−1110−11$ to 1, weak to EM

(b) 1 to 1

6.

(a) $2.09×10−5s2.09×10−5s$

(b) $4.77×104Hz4.77×104Hz$

8.

78.0 cm

10.

$1 . 40 × 10 6 1 . 40 × 10 6$

12.

100 GeV

13.

67.5 MeV

15.

(a) $1×10141×1014$

(b) $2×10172×1017$

17.

(a) $1671 MeV 1671 MeV$

(b) $Q = 1, Q′ = 1 + 0 + 0 = 1. L τ = − 1; L′τ = − 1; Lμ = 0; L′μ = − 1 + 1 = 0 Q = 1, Q′ = 1 + 0 + 0 = 1. L τ = − 1; L′τ = − 1; Lμ = 0; L′μ = − 1 + 1 = 0$

(c)

19.

(a) 3.9 eV

(b) $2.9×10−82.9×10−8$

21.

(a) The $uuduud$ composition is the same as for a proton.

(b) $3.3×10−24s3.3×10−24s$

23.

a) $Δ++(uuu);B=13+13+13=1Δ++(uuu);B=13+13+13=1$

b)

25.

(a) $+1+1$

(b) , all lepton numbers are 0 before and after

(c) $(sss)→(uds)+u-s(sss)→(uds)+u-s$

27.

(a) $(uu-+dd¯)→(uu-+dd¯)+(uu-+dd¯)(uu-+dd¯)→(uu-+dd¯)+(uu-+dd¯)$

(b) 277.9 MeV

(c) 547.9 MeV

29.

No. $Charge=−1Charge=−1$ is conserved. $Lei=0≠Lef=2Lei=0≠Lef=2$ is not conserved. $Lμ=1Lμ=1$ is conserved.

31.

(a)Yes. $Z=−1=0+(−1)Z=−1=0+(−1)$, $B=1=1+0B=1=1+0$, all lepton family numbers are 0 before and after, spontaneous since mass greater before reaction.

(b) $dds→udd+u-ddds→udd+u-d$

33.

(a) 216

(b) There are more baryons observed because we have the 6 antiquarks and various mixtures of quarks (as for the π-meson) as well.

35.

$Ω + ( s - s - s - ) B = − 1 3 − 1 3 − 1 3 = − 1, L e , μ , τ = 0 + 0 + 0 = 0, Q = 1 3 + 1 3 + 1 3 = 1, S = 1 + 1 + 1 = 3 . Ω + ( s - s - s - ) B = − 1 3 − 1 3 − 1 3 = − 1, L e , μ , τ = 0 + 0 + 0 = 0, Q = 1 3 + 1 3 + 1 3 = 1, S = 1 + 1 + 1 = 3 .$

37.

(a)803 MeV

(b) 938.8 MeV

(c) The annihilation energy of an extra electron is included in the total energy.

39.

$c d ¯ c d ¯$

41.

a)The antiproton

b) $p-→π0+e−p-→π0+e−$

43.

(a) $5×10105×1010$

(b) $5×104particles/m25×104particles/m2$

45.

$2.5 × 10 − 17 m 2.5 × 10 − 17 m$

47.

(a) 33.9 MeV

(b) Muon antineutrino 29.8 MeV, muon 4.1 MeV (kinetic energy)

49.

(a) $7.2×105kg7.2×105kg$

(b) $7.2×102m37.2×102m3$

(c) $100 months100 months$

53.

(a)

(b)

(c)

(d) The proton has a positive charge, and the antiproton has a negative charge.

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