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: the object transferred some of its energy to its surroundings.
Explanation:
answer:
6 ohms
Explanation:
if these two resistors are connected in series, the total resistance is the sum: 2+4 = 6 (ohms)
It would be "Researchers found environmental safe replacements for CFC's"