When you lift a book from the ground to your desk, what kind of work do you do, negative or positive? by lifting the book, what do you change? does the book gain or lose energy? what kind of energy?

i really only need with the last 3, but any is appreciated.

What is the earliest point in the universe that we can observe? why can’t we see back further than this?

Question 1 (5 pts): what is the maximum distance for which you can you resolve the two individual headlights of an on-coming truck as two separate lights rather than one if the headlights are separated by 2.00 m and your eye has a diameter of 1.00 centimeter? assume a wavelength of 500 nm.

Photons with the highest energy have the longest period