She could tell by how many components she put in. The compounds, are like the ingredients. The Mixture is all the ingredients stirred together.
Here, ball is released... and it is in free fall means with zero initial velocity.
We know, s = ut + 1/2 at²
Here, s = 1000 m
u = 0
a = 10 m/s2
Substitute their values,
1000 = 0 + 1/2 * 10 * t²
2000 = 10 * t²
t² = 2000 /10
t = √200
t = 14.14 s
In short, Your Answer would be 14.14 seconds
Hope this helps!
The added weight of the sand puts more downward pressure on the wheels contacting the rails, which would cause the trains speed to decrease.