the size, length, or amount of something by measuring
a unit or system of measuring
Applying conservation of momentum;

Where m1 = 80.0 kg; v1 =4.10 m/s; m2 = 130.0 kg; v2 = 0; mf = (80+130) kg; vf = ??
Therefore,
80*4.1 + 130*0 = 210*vf
vf = (80*4.1)/210 = 1.56 m/s
Answer:
D. Cold, dry air
(Just took the quiz and got it right, hope this helps :3)
Power = energy/time=20/4=5.0
False. They are arranged in a structure called a crystal lattice