2024智慧树网课答案 现代物理学 最新完整智慧树知到满分章节测试答案

第一章 单元测试

1、 问题:As a high-speed spaceship flies past you, it fires a strobe light that sends out a pulse of light in all directions. An observer aboard the spaceship measures a spherical wave front that spreads away from the spaceship with the same speed in all directions. What is the shape of the wave front that you measure? （ ）
选项：
A:spherical
B:ellipsoidal, with the longest axis of the ellipsoid along the direction of the spaceship’s motion;
C:ellipsoidal, with the shortest axis of the ellipsoid along the direction of the spaceship’s motion
D:not enough information is given to decide.
答案: 【
spherical
】

2、 问题:Stanley, who works for the rail system, has carefully synchronized the clocks at all of the rail stations. At the moment that Stanley measures all of the clocks striking noon, Mavis is on a high-speed passenger car traveling from Ogdenville toward North Haverbrook. According to Mavis, when the Ogdenville clock strikes noon, what time is it in North Haverbrook?（ ）
选项：
A:noon
B:before noon
C:after noon
D:not enough information is given to decide
答案: 【
after noon
】

3、 问题:Samir (who is standing on the ground) starts his stopwatch at the instant that Maria flies past him in her spaceship at a speed of 0.600c. At the same instant, Maria starts her stopwatch. As measured in Samir’s frame of reference, what is the reading on Maria’s stopwatch at the instant that Samir’s stopwatch reads 10.0 s? （ ）
选项：
A:10.0 s
B:less than 10.0 s
C:more than 10.0 s
D:not enough information is given to decide
答案: 【
less than 10.0 s
】

4、 问题:In frame S events P₁ and P₂ occur at the same x-, y- and z-coordinates, but event P₁ occurs before event P₂. In frame S’, event P1 occurs first。（ ）
选项：
A:对
B:错
答案: 【
对
】

5、 问题:According to relativistic mechanics, when you double the speed of a particle, the magnitude of its momentum increases by （ ）
选项：
A:a factor of 2
B:a factor greater than 2
C:a factor between 1 and 2 that depends on the mass of the particle
D:a factor smaller than 1
答案: 【
a factor greater than 2
】

第二章 单元测试

1、 问题:Silicon films become better electrical conductors when illuminated by photons with energies of 1.14 eV or greater, an effect called photoconductivity. Which of the following wavelengths of electromagnetic radiation can cause photoconductivity in silicon films?（ ）
选项：
A:ultraviolet light with λ = 300 nm
B:red light with λ = 600 nm
C:infrared light with λ = 1200 nm
答案: 【
ultraviolet light with λ = 300 nm
red light with λ = 600 nm
】

2、 问题:In the apparatus used to produce x rays, similar to Röntgen’s 1895 apparatus, suppose you increase the number of electrons that are emitted from the cathode per second while keeping the potential difference V_AC the same. How will this affect the intensity I and minimum wavelength λ_min of the emitted x rays? （ ）
选项：
A:I and λ_min will both increase
B:I will increase but λ_min will be unchanged
C:I will increase but λ_min will decrease
D:I will remain the same but λ_min will decrease
E:none of these
答案: 【
I will increase but λ_min will be unchanged
】

3、 问题:If you used visible-light photons in the Compton-effect experiment, the photons would undergo a wavelength shift due to the scattering.（ ）
选项：
A:对
B:错
答案: 【
对
】

4、 问题:If you used visible-light photons in the Compton-effect experiment, it is possible to detect the shift with the human eye。（ ）
选项：
A:对
B:错
答案: 【
错
】

5、 问题:Through which of the following angles is a photon of wavelength λ most likely to be deflected after passing through a slit of width a? Assume that is much less than a. （ ）
选项：
A:θ=λ/a
B:θ=3λ/2a
C:θ=2λ/a
D:θ=3λ/a
E:not enough information given to decide
答案: 【
θ=3λ/2a
】

第三章 单元测试

1、 问题:A proton has a slightly smaller mass than a neutron. Compared to the neutron, would a proton of the same wavelength have （ ） ?（ ）
选项：
A:more kinetic energy
B:less kinetic energy
C:the same kinetic energy
答案: 【
more kinetic energy
】