Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

1)Suppose a certain laser can provide 80 TW of power in 1.2 ns pulses at a wavel

ID: 2013689 • Letter: 1

Question

1)Suppose a certain laser can provide 80 TW of power in 1.2 ns pulses at a wavelength of 0.29 µm. How much energy is contained in joules in a single pulse?

2)The maximum electric field 12 m from a point light source is 1.8 V/m. What are (a) the maximum value of the magnetic field and (b) the average intensity of the light there? (c) What is the power of the source?

3)In Fig. 33-40, initially unpolarized light is sent into a system of three polarizing sheets whose polarizing directions make angles of ?1 = ?2 = ?3 = 62° with the direction of the y axis. What percentage of the initial intensity is transmitted by the system? (Hint: Be careful with the angles.)

4)Figure 33-49 shows light reflecting from two perpendicular reflecting surfaces A and B. Find the angle (in o) between the incoming ray i and the outgoing ray r'.

5)In Fig. 33-57, a ray of light is perpendicular to the face ab of a prism (n = 1.43). Find the largest value for the angle ? so that the ray is totally reflected at face ac if the prism is immersed (a) in air and (b) in water (n=1.33).


Explanation / Answer

1 ) A laser can provide a Power P = 80.0 TW                                                      = 80.0 *10^12 W    time t = 1.2 ns               = 1.2*10^-9 s Energy contained in a single pulse is                        E   = P * t                              = 80.0 *10^12 W * 1.2 *10^-9 s                              = 9.6*10^4 J 2 ) Given that maximum electric feld is E = 1.8 V /m a ) Maximum magnetic field is B = E / c                                                      = 1.8 V /m / 3.0*10^8 m/s                                                       = 0.6*10^-8 T b ) Average intensity of the light is S = E B / 2_0                                                            = 1.8 V /m * 0.6*10^-8 T / 2 *4*10^-7                                                            = 4.299*10^-3 W /m^2 c ) Power of the source is P = S A                                                  = 4.299*10^-3 W /m^2 * 4 ( 12.0m)^2                                                  = 2.376*10^-6 W please post questions with figures