Answer:
9.4 N
Explanation:
m = mass of the book = 1.83 kg
= Coefficient of static friction = 0.522
= Coefficient of kinetic friction = 0.283
= Static frictional force
F = force needed to make the book move
force needed to make the book move is same as the magnitude of maximum static frictional force applied by the desk on the book
Static frictional force is given as
=
mg
Hence, the force need to move the book is given as
F = =
mg
F = mg
F = (0.522) (1.83 x 9.8)
F = 9.4 N
To solve this problem it is necessary to apply the relationship given by the intrinsic carrier concentration, in each of the phases.
The intrinsic carrier concentration is the number of electrons in the conduction band or the number of holes in the valence band in intrinsic material. This number of carriers depends on the band gap of the material and on the temperature of the material.
In general, this can be written mathematically as
Both are identical semiconductor but the difference is band gap which is:
The ratio between the two phases are given as:
Therefore the ratio of intrinsic carrier densities for the two materials at room temperature is 0.145