This problem must be solved using a sketch. I attached an illustration of the problem.
You must trace the ray that reflects from the top off the table to your eyes. This how eyesight works, light rays reflects off the objects into your eyes.
Law of reflection tells us that light ray reflects off the surface at the same angle in which it falls on it( i attached another illustration of this).
Now we can write tangens equations:

We solve for h:
Answer:
1⁺ ion
Explanation:
Metals in the first group on the periodic table will prefer to form 1⁺ ion. This is because the 1 valence electron in their orbital.
Most metals are electropositive and would prefer to lose electrons than to gain it.
Like all metals, the group 1 elements called the alkali metals would prefer to lose and electron.
On losing an electron the number of protons is then greater than the number of electrons. This leaves a net positive charge.
Answer:
175.96 g
Explanation:
Potential energy required for the man to climb 7.07 km = m g h.
= 64 x 9.8 x 7070
= 4.434 x 10⁶ J
= 4.434 X 10⁶ / 4.2 cals
= 1.0557 x 10⁶ cals
= 1.0557 x 10⁶ / 6000 g of butter
= 175.96 g of butter.
The work function is what we call the minimum energy that is required by an electron to leave the metal target in the photoelectric effect.