1 2500kg railroad car moving with a speed of 3 m/s is linked with a 3500 kg railroad car moving toward the first car with a speed by 1 m/s. Both are moving along a straight track. Find the speed of the two cars just after they link up.

How many atoms of nitrogen are in the chemical formula ni(w on

Emmy kicks a soccer ball up at an angle of 45° over a level field. she watches the ball's trajectory and notices that it lands, two seconds after being kicked, about 20 m away to the north. assume that air resistance is negligible, and plot the horizontal and vertical components of the ball's velocity as a function of time. consider only the time that the ball is in the air, after being kicked but before landing. take "north" and "up" as the positive ‑ and ‑directions, respectively, and use ≈10 m/s2 for the downward acceleration due to gravity.

Uwill get answer it brainliest will be awarded for →calculate the pressure exerted by a body having a mass of 30kg over an area of contact 400cm2.also explain it for every step there should be