Saved Bookmarks
| 1. |
A short light pulse of enegry E = 7.5J falls in the form of a narrow and almost parallel beam on a mirror plate whose reflection coefficient is rho = 0.60. The angle of incidence is 30^(@). In terms of the corpuscular theory find the momentum transfered to the plate. |
|
Answer» SOLUTION :The momentum transferred to the plate is ` underset(("momentum transfered on ab sor ption")) underset(darr)(=(E)/(c )(1-rho){sin theta HTI - COS theta hatj})underset(("momentum transfered on reflection")) underset(darr) (+(E)/(c )rho{12cos theta hatj})` `=(E)/(c)(1-rho) sin theta hatj - (E)/(c)(1-P) cos theta hatj` Its MAGNITUDE is `(E)/(c)sqrt((1-rho)^(2)sin^(2)theta+(1+rho)^(2)cos^(2)theta) = (E)/(c)sqrt((1-rho)^(2)+2rho cos 2 theta)` SUBSTITUTION gives `35n` N.s as the answer. 
|
|