# 急需高手,三題英文物理問題（20點）

1. Using monochromatic light of 410 nm wavelength, a single thin slit forms a diffraction pattern, with the first minimum at an angle of 40.0 from central maximum. The same slit, when illuminated by a new wavelength, produces a diffraction pattern with the second minimum at 60 angle from the central maximum. What is the wavelength if this new light?

A. 342 nm

B. 309 nm

C. 326 nm

D. 276 nm

E. 293 nm

2. A light beam with wavelength 500 nm us reflected constructively from a thin layer of oil having index of refraction 1.25. The oil floats on the top of water of index of refraction 1.33. What is the minimum thickness of the layer of oil?

A. 100 nm

B. 200 nm

C. 225 nm

D. 150 nm

E. 175 nm

3. A particle is moving at 0.86c. By what magnitude percentage is the Newtonian expression (p=m0v) for momentum in error? (The percentage error is the difference between the erroneous and correct expressions, relative the correct one).

A. 49%

B. 62%

C. 40%

D. 55%

Update:

http://www.chegg.com/homework-help/questions-and-a...

Update 2:

As shown in the figure, the orientation of the transmission axis for each of three ideal polarizing sheets is labeled relative to the vertical direction. A beam of light, polarized in the vertical direction, is incident on the first polarizer

with an intensity of 1.00 kW/m2.

Update 3:

What is the intensity of the beam after it has passed through the three polarizing sheets when θ1 = 30°, θ2 = 30°, and θ3= 60°?

A) 563 W/m2

B) 141 W/m2

C) 316 W/m2

D) 188 W/m2

E) 433 W/m2

Update 4:

http://tw.knowledge.yahoo.com/question/question?qi...