Intermolecular forces are forces that keep molecules together. For example, the forces between two water molecules. The stronger the intermolecular forces are, the more "solid" is the matter going to be, meaning that the intermolecular forces are the strongest in solids and weakest in gases.
Make sure not to confuse intERmolecular forces (forces between *molecules*) and intRAmolecular forces (forces between *atoms* that make up a molecule).
Answer:
29.16 J
Explanation:
From Hook's law,
W = 1/2(ke²)..................... Equation 1
Where W = work done, k = Spring constant, e = extension.
Given: W = 9 J, e = 0.5 m.
Substitute into equation 1
9 = 1/2(k×0.5²)
Solve for k
k = 18/0.5²
k = 72 N/m.
The work done required to stretch the spring by additional 0.4 m is
W = 1/2(72)(0.4+0.5)²
W = 36(0.9²)
W = 29.16 J.
Answer:
Explanation:
Given
Em wave is in the form of
where 
Wave constant for EM wave k is
Wavelength of wave 
The medium determines the speed of the wave traveling in it, which also can have a number of other effects, including how much the wave bends (refracts), whether it reflects, etc.
Because waves move through space, they must have a velocity. The velocity of a wave is a function of the type of wave, and the medium it travels through. Electromagnetic waves moving through a vacuum, for instance, travel at roughly 3 x
10
8
m/s. This value is so famous and common in physics it is given its own symbol, c.
