Why does your urine curve when you pee?

Answer 1

Same reason the flow of water from a hose curves, or liquid poured from a pitcher or a bottle. Same reason a thrown ball makes an arc, and an arrow fired from a bow. You have some forward thrust behind it, stronger than the downward pull of gravity. After a little while the momentum weakens, and then the pull of gravity is stronger. This makes a curve. If it happened all at once, you'd see a right angle--a square corner where the horizontal push stopped and the downward pull began. That would really look funny.