1) By looking at the table of the visible spectrum, we see that blue light has a wavelength in the range [450-490 nm], while red light has wavelength in the range [620-750 nm]. Therefore, red light has longer wavelength than blue light.
2) The frequency f of an electromagnetic wave is related to its wavelength

by the formula

where c is the speed of light. We see that the frequency is inversely proportional to the wavelength, so the shorter the wavelength, the greater the frequency. In this case, blue light has shorter wavelength than red light, so blue light has greater frequency than red light.
3) The energy of the photons of an electromagnetic wave is given by

where h is the Planck constant and f is the frequency. We see that the energy is directly proportional to the frequency, so the greater the frequency, the greater the energy. In this problem, blue light has greater frequency than red light, so blue light has also greater energy than red light.
Constant velocities is an objects velocity is not changing.This means it is moving at the same speed.
Constant acceleration means that it is increasing by the same value.so the speed increases by the same amount every second
Constant position means it is not moving so it does not have any velocity at all so 0 velocity.
The current is defined as the ratio between the charge Q flowing through a certain point of a wire and the time interval,

:

First we need to find the net charge flowing at a certain point of the wire in one second,

. Using I=0.92 A and re-arranging the previous equation, we find

Now we know that each electron carries a charge of

, so if we divide the charge Q flowing in the wire by the charge of one electron, we find the number of electron flowing in one second:
Answer:
The electric force between them if the pieces of grain are 2 cm apart is
.
Explanation:
Given:
Charge on one grain, 
Charge on another grain, 
Separation between them, 
Electric force acting between two charges
separated by a distance
is given as:

Where,
is Coulomb's constant equal to
.
Now, plug in all the values and solve for
.

Therefore, the electric force between them if the pieces of grain are 2 cm apart is
.