Answer:
13.9 m/s
Step-by-step explanation:
The velocity of the train along the inclined surface is given by the ratio between the distance travelled, d, and the time taken, t:

where we have
d = 400 m
t = 5 s
Substituting,

This is the velocity of the train along the inclined plane. Now we can find the vertical component of the velocity by using the formula:

where
is the angle of the slope. Substituting, we find
