B. The hormone erythropoeitin increases the production of red blood cells when oxygen levels are low.
Answer:
13.9 m/s
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

Answer:
Speed of the soccer ball with respect to ground is ZERO
Explanation:
As we know that truck is moving with speed 20 mph
Now a soccer ball is shoot from truck with respect to the motion of truck in opposite direction
The relative speed of the soccer ball is

now we know that

so we have

so we have
