The longest visible rays, at the end of the visible spectrum are `7.8xx10^(-7)` m in length. Explain this length in micrometers

The longest side of a triangle is 3 times the shortest side and the third side is 2 cm shorter than the longest side. If the perimeter of the triangle is at least 61 cm, find the minimum length of the shortest side.

A thin film is 4,000 overset @A thick. White light from an extended source falls normally on the film.If the refractive index of film is 1.5,what wavelength within the visible spectrum will be intenisifed in the reflected beam ,if visible range of the spectrum is 3,900 overset @A to 7,800 overset @A ?

A wire having a mass of 0.45 kg posseses a resistanfce of 0.014 Omega . If the resistivity of the material fo wire is 1.78 xx10^-7 Omegam , calculate its length and radius. Given that the density of the material of wire is 8.93 xx10^3 kg m^-3

Draw a line segment of length 7.3 cm using a ruler.

The tensile strength of steel is 5 xx 10^7 N m^-2 . Find the maximum length of the wire that can hang vertically , without breking it. Densityof steel is 8 xx 10^3 kg m^-3.

The wave emtted by any atom or molecule must have some finite total length .For sodium light this length(called coherne length)is 2.4 cm.Deduce the cohernece time.Given that gamma=5*9 xx 10^(-7) cm and c=3.0 xx 10^8 m s^(-1) .

About 5% of the power of a 100 W light bulb is converted to visible radiation. What is the average intensity of visible radiation at a distance of 10 m? Assume that the radiation is emitted isotropically and neglect reflection.