Suppose two loaded train cars are moving toward one another, the first having a mass of 1.50 \times 10^5\, \mathrm{kg}1.50×10 5 kg and a velocity of (0.11 \, \mathrm{m/s})\, \hat{i}(0.11m/s) i ^ , and the second having a mass of 1.10 \times 10^5\, \mathrm{kg}1.10×10 5 kg and a velocity of (-0.21 \, \mathrm{m/s})\, \hat{i}(−0.21m/s) i ^ . what is their final velocity?

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 !

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?

Explain what will happen if decomposers were apsent from a forest ecoysystem.