Answer:
attached below is the free body diagram of the missing illustration
Initial kinetic energy of the electron = 3 eV
Explanation:
The conclusion that can be drawn about the kinetic energy of the electron is

E
= initial kinetic energy of the electron
E
= -4 eV
E
= -1 eV
insert the values into the equation above
= -1 -(-4) eV
= -1 + 4 = 3 eV
Answer:
4.71 eV
Explanation:
For an electromagnetic wave with wavelength

the energy of the photons in the wave is given by

where h is the Planck constant and c the speed of light. Therefore, this is the minimum energy that a photon should have in order to extract a photoelectron from the copper surface.
The work function of a metal is the minimum energy required by the incident light in order to extract photoelectrons from the metal's surface. Therefore, the work function corresponds to the energy we found previously. By converting it into electronvolts, we find:

Answer:
0.2
Explanation:
Horizontal force=100N
Weight of crate=500 N
We have to find the coefficient of kinetic friction.
Normal ,N=Weight=500N
Horizontal force,
Where
=Horizontal force
N=Normal force
=Coefficient of kinetic friction
Substitute the values in the formula


Hence, the coefficient of kinetic friction =0.2
The magnetic field generated by a wire carrying a current I is:

where r is the distance at which the magnetic field is measured, and

is the magnetic permeability in vacuum.
The problem says that the magnetic field at a distance r=12 cm=0.12 m from the wire must be no larger than

. Substituting these values, we can find the maximum value of the current I that the wire can carry: