Suggest a way to measure:
a. the thickness of a sheet of paper,
b. the distance between the sun and the moon.

The distance between the Earth and the Moon is

Find the distance between Venus and Sun.

The distance between the genes is measured by

_________ is defined as the average distance between the earth and the sun.

What is the distance between A (4,0) and B (8, 0).

Name the unit which is used to measure distance between the two stars.

When the sun is directly overhead, the surface of the earth receives 1.4 xx (10^3) W (m^-2) of sunlight. Assume that the light is monochromatic with average wavelength 500mn and that no light is absorbed in between the sun and the earth's surface. The distance between the sun and the earth is 1.5 xx (10^11) m. (a) Calculate the number of photons falling per second on each square metre of earth's surface directly below the sun. (b) How many photons are there in each cubic metre near the earth's surface at any instant? (c) How many photons does the sun emit per second?

In a Young's double slit experiment using monochromatic light, the fringe pattern shifts by as certasin distance on the screen when a mica sheet of refractive inde 1.6 and thickness 1.964 micron (1 micron =10^-6m) is introduced in the path of one of the interfering waves. The mica sheet is then removed and the distance between the screen and the slits is doubled. It is found that the distance between the successive maxima now is the same as the observed frige-shift upon the introduction of the mica sheet. Calculate the wavelength of the monochromatic light used in the experiment.

A new unit of length is chosen such that the speed of light in vscuum is unity. What is the distance between the sun and the Earth in terms of the new unit if light takes 8 min and 20 s to cover this distance.