Two trains are on separate but parallel tracks running east and west. One has a speed of 90 km/h, the other 80 km/h. Initially, the trains are 5 km apart and are approaching each other. How long will it take the two trains to have the same position along the east-west direction?

Find v(t), given acceleration a(t)=7j and initial velocity v(0)=k

The diagram shows a series of volcanic island and a hot spot determine the direction of movement of the tectonic plate that for the island

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 !