The speed of light in a certain type of glass is 40% slower than the speed of light in air. The index of refraction for that type of plastic is about

divide the right side by the left side

0.024÷1.2=0.02 for example

igneous rocks also form where plates converge. the subducting plate melts as it sinks into the crust of the earth, and the melt rises into the overriding plate forming volcanoes. metamorphic rocks are formed mainly in the lithosphere, wherever there is high pressure and high temperature. -woods

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach