I added individual steps for clarity. Note that g must be positive if the solution is to be real.

Let me know if you have any questions.
Hubble noticed that the galaxies were moving away from us, which meant the universe was expanding.
This is why constellations change over time. In some years, the Big Dipper won't actually look like a dipper anymore.
Answer:
Friction force is independent of the direction of the contacting surfaces
Explanation:
It can go any way depending on how much force is being out on it.