英文大物试题

1、A chamber’s volume is 10 cm3and it contains atmosphere. The chamber is drawn through a vacuum pump to a pressure p=5×10-6mmHg at temperature T=300K . Find: (1) The number of molecules in the chamber at this time. (2) The total translational kinetic energy of all molecules. (3) Total rotational kinetic energy. (4) Total kinetic energy. (6 points)

2、An engine carriers 1.00 mol of ideal monatomic gas around the cycle shown in following Fig. 1. If T c=600K, try to calculate: (1) The heat absorbed during process ab bc ca. (2) The work done by the engine during a cycle. (3) The efficiency of the engine.

3、The curve of two SHMs with the same frequency and vibration direction are shown in the following Fig.2. Write the vibration equation respectively and the equation of their superposition vibration.

4、The wave form of a plane harmonic wave at t=0.001s is shown in Fig. 3. Suppose its frequency is 250Hz, and the point P is moving AWAY its equilibrium position now.(1) Write the wave equation; (2) Write the expression of the vibration equation and the vibration velocity of the point who is 100m from the origin.

5、A cylindrical concave lens A is placed on a plate glass B, the radius of curvature of the lens is R. A parallel monochromatic light whose wavelength is λ inc idents normally to the air film, then the interference fringes due to the air film between A and B are observed, as shown in the Fig.. If the largest thickness of the air film d=2λ, try to answer the questions:(1) What’s the shape of the interference fringes?(2) The position of the bright fringes and dark fringes(shown by r).(3) How many bright fringes can be seen? (4) How would the fringes change when the plate glass B is moved down in parallel?

6、A parallel monochromatic light incident normally to a slit of a=1.0mm. Behind the slit, a convex lens whose focal length is 100cm is used to focus the diffracted light on the screen. Suppose the distance between the 3rd dark fringes is 0.3cm, calculate:(1) The wavelength of the incident light. (2) The width of the center bright fringe. （10 points）

7、The total energy of a harmonically oscillating body is 3×10-5 J and the maximum force acting on the body is 1.5×10-3 N. Write the equation of motion of this body if the period of oscillation is 2 s and the initial phase is 60º.

8、Find the amplitude and the initial phase of the harmonic oscillation obtained by the summation of identically directed oscillation confirming to the equations x1=0.02sin(5πt+π/2) m and x2=0.03cos(5πt+π/4) m

9、The equation of a planar simple harmonic wave is given by y=6.0cos(0.02πx+4.0πt), where x and y are expressed in centimeters and t in seconds. Calculate:

(1) the amplitude, the wavelength, the frequency and the wave speed of this wave.

(2) the initial phase of the particle where x=10cm.

(3) the maximum vibration velocity of particles.

10、A plane cosine wave whose period is 2 seconds propagates along +x axis, its wave form at t=1/3 seconds is shown in the

following figure.