Awave is moving at the rate of 40 cm/s. its wavelength is 8cm. what is the frequency of the wave?
a. 5 hz
b. 320 cm
c. 5 cm
d. 320 hz

The correct answer is 5 Hz.

Explanation:

The expression for the relation between the speed and wavelength is as follows:

Here, v is the speed of the wave, f is the frequency of the wave and is the wavelength.

In the given problem, a wave is moving at the rate of 40 cm/s. Its wavelength is 8 cm.

Put v= 40 cm/s and =  8 cm.

Therefore, the correct option is (A).

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.