That's wave 'diffraction'.
Answer:
16km/h
Explanation:
Vt=20km/h ---train speed
Vd=4km/h
Donas speed relative to ground is:
Vrd=Vt-Vd
Donas is moving in opposite direction of train .
Vrd=20km/h-4km/h
Vrd=16km/h
Prior to determining the
experimental design, a scientist typically forms a hypothesis. The answer is
letter B. this is to prepare the scientist, the possible outcome of their
research before the experimental design whether they are wrong or not.
Answer:
the spring constant k = 
the value for the damping constant 
Explanation:
From Hooke's Law

Thus; the spring constant k = 
The amplitude is decreasing 37% during one period of the motion


Therefore; the value for the damping constant 
Im pretty sure its A cuz is closer to the earth.