An optical fibre with refractive index 1.72 is surrounded by a glass coating having refractive index 1.50.find the critical angle for total internal reflection at the fibre-glass interface.

What do you think car designers do if the damage caused by a crash test is too severe?

Determine the age of a fossil if it had only one eighth of its original carbon-14 content remaining?

Suppose a diode consists of a cylindrical cathode with a radius of 6.200×10^−2 cm , mounted coaxially within a cylindrical anode with a radius of 0.5580 cm . the potential difference between the anode and cathode is 260 v . an electron leaves the surface of the cathode with zero initial speed (v initial=0). find its speed vfinal when it strikes the anode.