(a) The force exerted by the electric field on the electron is given by the product between the electron charge q and the intensity of the electric field E:

Under the action of this force, the electron moves by:

And the work done by the electric field on the electron is equal to the product between the magnitude of the force and the displacement of the electron. The sign has to be taken as positive, because the direction of the force is the same as the displacement of the electron, so:

(b) The electron is initially at rest and it starts to move under the action of the electric field. This means that as it moves, it acquires kinetic energy and it loses potential energy. The change in potential energy is the opposite of the work done by the electric field:

Where Uf and Ui are the final and initial potential energy of the electron.
(c) For the conservation of energy, the sum of the kinetic energy and potential energy of the electron at the beginning of the motion and at the end must be equal:

(1)
where Ki and Kf are the initial and final kinetic energies.
The electron is initially at rest, so Ki =0, and we can rewrite (1) as

and by using the mass of the electron me, we can find the value of the final velocity of the electron:
Answer:
rods are more light sensitive than cones.
Explanation:
There are two types of photo receptors in retina of our eyes. 1 Rods and 2 Cones. Rods are about 120 million and they are more sensitive then the cones. But the rods are not sensitive to color. Cones help us in seeing the color and there are about 6 to 7 million cones that provide color sensitivity to our eyes. That is why in the dark or where their are dim levels of illumination rods provide us scotopic vision. Because rods are more light sensitive then the cones.
-- Since it's a cube, its length, width, and height are all the same 4 cm .
-- Its volume is (length x width x height) = 64 cm³ .
-- Density = (mass) / (volume)
= (176 g) / (64 cm³)
= 2.75 gm/cm³ .
Answer:
The angle of refraction is 41.68°.
Explanation:
The refractive index for water is
, and for air
: the angle of light with the normal is
; therefore Snell's law gives





