This is a 2 part question. A 4000kg truck has a head on inelastic collision with a 2500kg truck. the 4000kg truck moving at 20m/s and the 2500kg is going at 35 m/s. :
A. calculate the total momentum of the trucks before they collide.
B calculate thier speed just after they collide.

Which of the following is considered to be a vector?               a.  temperature    b.  velocity    c.  time    d.  mass

What are atoms of the same element with varying number of neutrons

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 !