Answer:
Work Function = 3.53 x 10⁻¹⁹ J = 2.2 eV
Explanation:
The work function of the metal metal can be found as follows:
Energy of Photon = Work Function + K.E
hc/λ = Work Function + K.E
Work Function = hc/λ - K.E
where,
h = Plank's Constant = 6.625 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = wavelength of photons = 240 nm = 2.4 x 10⁻⁷ m
K.E = Maximum Kinetic Energy = (2.97 eV)(1.6 x 10⁻¹⁹ J/1 eV) = 4.752 x 10⁻¹⁹ J
Therefore,
Work Function = (6.625 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(2.4 x 10⁻⁷ m) - 4.752 x 10⁻¹⁹ J
Work Function = 8.281 x 10⁻¹⁹ J - 4.752 x 10⁻¹⁹ J
<u>Work Function = 3.53 x 10⁻¹⁹ J = 2.2 eV</u>
Explanation:
Below is an attachment containing the solution.
The magnetic flux through an area A is given by

where
B is the magnitude of the magnetic field
A is the area

is the angle between the direction of B and the perpendicular to the surface A.
In our problem, the area lies in the x-y plane, while B is in the z direction, this means that B and the perpendicular to A are parallel, so

and

, so we can rewrite the formula as

We can calculate the area starting from the radius:

And then using the intensity of the magnetic field given by the problem,

, we find the magnetic flux:
Velocity = displacement / time
displacement = velocity × time
d = 29 ms⁻¹ ˣ 8.4 s
d = 243.6 m
Since friction is something rubbing against each-other with resistance the answers would be... b, and e