An electric model train travels at 31.50 cm/s around a circular track of radius 1.670 m. how many revolutions does it perform in one second

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 !

Which planet do you think would be easiest for humans to colonize some day?

Wind and moving water provide energy. question 1 options: chemical mechanical thermal none of the above