A microscope using suitable photons is employed to locate an electron in an atom within a distance of 0.1 A .what is the uncertainty involved in the measurement of its velocity .

Explanation

A fluid will stick to a solid surface if the surface energy , between fluid and the solid is smaller than the sum of surface energies between solid air and fluid air

Moreover there is cohesion between the solid surface and the liquid. A flat vertical glass plate, below which a vessel of some liquid is kept , forms one arm of the balance.
The plate is balanced by weight on the other side , with its horizontal edge just over water.
The vessel is raised slightly till the liquid just touches the glass plate and pulls it down a little because of surface tension .Weights are added till the plate just clears water.
Suppose the additional weight required is W. The surface tension of the liquid -air interface is
`S_(la)=(W)/(2l)=(mg)/(2l)" " (l-"liquid",a -"air")`
Where m is the extra mass and l is the length of the plate edge.
By placing the values of m, g and l surface tension `S_(la)` can be determined.