Answer:
3 photons
Explanation:
The energy of a photon E can be calculated using this formula:

Where
corresponds to Plank constant (6.626070x10^-34Js),
is the speed of light in the vacuum (299792458m/s) and
is the wavelength of the photon(in this case 800nm).

Tranform the units

The band Gap is 4eV, divide the band gap between the energy of the photon:

Rounding to the next integrer: 3.
Three photons are the minimum to equal or exceed the band gap.
Answer:
1.) 6 hectokisses 50 times
2.) Millionaire
Explanation:
Okay so don't quote me on this but I believe the answer is A) I'm saying this because B and C make no sense. and you can't change the mass of something without changing it totally.
Answer:
The current is
The direction is anti-clockwise
Explanation:
The diagram for this question is shown on the first uploaded image
From the question we are told that
the length of the conducting rod is 
The resistance is 
The magnetic field is 
The speed of the rod is 
The emf induced is
substituting values we have


From ohm law the induced current would be

substituting values we have

The direction anticlockwise this because according to lenze law the current due to change in magnetic field will act in the opposite direction of the force causing the magnetic field to change