Question

A laser (electromagnetic wave) has the maximum electric field strength of 1.0x1011 V/m. What is the force the laser applies on a mirror (totally reflective) of 5.0 mm2 area? A. 2.76 x105N B. 1.21 x106N C. 1.94 x106N D.4.43 x105 N E. 7.82 x104N

Answer 1

Answer:

The correct option is  D

Explanation:

From the question we are told that

  The maximum electric field strength is  $E = 1.0 *10^{11} \ V/m$

   The  area is  $A = 5.0 \ mm^2 = 5.0 *10^{-6} \ m^2$

Generally the force the laser applies is mathematically represented as

       $F = \epsilon_o * E ^2 * A$

Here  $\epsilon_o = 8.85*10^{-12} C/(V \cdot m)$

      $F = 8.85*10^{-12} * (1.0 *10^{11}) ^2 * 5.00*10^{-6 }$

=>   $F = 4.43 *10^{5} \ N$