Calendar: 1873-1874 Page 559

applied sciences 559 will rise will be the same in both cases find the height when the velocity of projection is 800 feet per second Enunciate the third law of motion Two weights of 16 oz and 16j oz are attached to the extremities of string passing over smooth pulley find the distance through which the heavier weight will have descended in seconds and the velocity acquired iLigijt aitU 9stronomp SECOND AND THIRD YEARS What must be the angle between two plane mirrors in order that ray incident parallel to one of them may after two re- flections be parallel to the other How many images of the same object may be seen in the two mirrors Explain the reflection and refraction of light on the wave theory and describe the course of the waves after reflection or refraction If ray of light be refracted through prism the angle of incidence being given prove from the law of refraction by geo- metrical construction or otherwise that the deviation increases with the angle of the prism What is the limit of the angle of the prism if μ be greater than unity if μ be less than unity Ρ system of parallel rays is incident on refracting sphere Prove that there is certain angle of incidence for which the deviation is maximum when the pencil is once internally reflected Explain briefly the application of this proposition to the theory of the rainbow What is meant by pure spectrum How may pure spectrum of the sun be obtained upon screen Describe and account for its peculiar features beam of light falls equally on two plane mirrors inclined at very obtuse angle to one another and is reflected describe and account for the appearance on screen placed to receive the beam after reflection