Optics, Physics

A spider is hanging by means of its own silk thread directly above a transparent fixed sphere of r = 20cm .... the refractive index of material of sphere is root(2).... and height of the spider is 2r = 40cm .... an insect initially sitting at the bottom directly below the spider starts crawling along vertical circular path with constant speed pi/4 cm/s.. for how long will the insct be invisible to the spider. Assume that it crawls once around the circle .

Solution) Spider is able to see only half of the sphere which is topmost hemispherical surface. when insct enters in bottom hemispherical surface it becomes invisible for the spider. a/c question insct is travelling vertical circular path it travels pi/4cm in 1sec.then it will travel 2pi r dist i.e. 40picm in 160sec. hence it will travel pi r i.e20pi (half circle) in 80s.

Posted Date: 3/11/2013 1:50:28 AM | Location : United States







Related Discussions:- Optics, Assignment Help, Ask Question on Optics, Get Answer, Expert's Help, Optics Discussions

Write discussion on Optics
Your posts are moderated
Related Questions
Working of terrestrial telescope

A confined quantity of air undergoes two thermodynamic processes departing from an initial equilibrium state where the temperature is 20°C, the absolute pressure is 1bar, and the v


Weber; Wb (after W. Weber, 1804-1891): The derived SI unit of magnetic flux equivalent to the flux that, relating a circuit of one turn, generates in it an electromotive force


The Sodium chloride structure   NaCl is an ionic crystal and in this crystal the sodium and chlorine ions are located side-by side in the FCC lattice. Like diamond it is also a

The cold filament resistance of a light bulb is 20.0). The bulb consumes 75 W when it is operating from a 120-V source. By what factor does the start-up current in the bulb

On the way to school, Jamal realizes that he left his physics homework at house. His car was initially heading north at 24.0 m/s. It takes him 35.5 s to turn his car around and hea

Lead acid batteries: Lead acid cells have a nominal voltage of 2 Volts, therefore a typical 24V aircraft battery would consist of 12 cells connected in series. The active mater

Consider a particle of energy E is incident from the left on a rectangular potential barrier of height and width and on both sides of this barrier at which means that no force act