Design a roller coaster.

i need with the questions on this page.

and also questions:
1. why does the first hill have to be the highest?
2. why can't the next hill of the roller coaster be as high as the first?
3. what forces slows it down?
4. the kinetic energy is change to what kind of energy by this force?
5. what is the approximate percentage of gpe/ke at different points on your roller coaster labeled a, b,c?

Which articulations allow for greatest range of motion?

This is important 1. what happens to the speed of molecules in water vapor when it condenses to form a liquid? (2 points) the molecules slow down. the molecules speed up. the molecules slow down and then speed up. the molecules speed up and then slow down. 2. how might human activities change to compensate for a decrease in water supplies? (2 points) humans might build a factory. humans might build drainage systems. humans might extract more water from the ground. human behavior does not change because of the water cycle. i'll be grateful if anyone can answer these 2 questions !

How can you increase the strength of an electromagnet?