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

beta is electron from nucleus

something from nucleus has changed, but charge must be same for cons of charge

i think the answer is a, hope this : )