Atrain moves with a constant velocity for 15s for 155m. how fast is the train moving?

10.3m/s

Explanation:

In theory and for a constant velocity the physics expression states that:

Eq(1):  distance  = velocity times time <=> d = v*t    for v=constant.

If we solve Eq (1) for the velocity (v) we obtain:

Eq(2):  velocity  = distance divided by time <=> v = d/t

Substituting the known values for t=15s and d=155m we get:

v = 155 / 15 <=> v = 10.3

in this image, you can see solar radiation going through ocean water.

no image, but probably absorption