Answer:
(a) 0
(b) 10ML
(c) 
(d) 
Explanation:
(a) When hanging straight down. The child is at the lowest position. His potential energy with respect to this point would also be 0.
(b) Since the rope has length L m. When the rope is horizontal, he is at L (m) high with respect to the lowest swinging position. His potential energy with respect to this point should be

where g = 10m/s2 is the gravitational acceleration.
(c) At angle
from the vertical. Vertically speaking, the child should be at a distance of
to the swinging point, and a vertical distance of
to the lowest position. His potential energy to this point would be:

(d) at angle
from the horizontal. Suppose he is higher than the horizontal line. This would mean he's at a vertical distance of
from the swinging point and higher than it. Therefore his vertical distance to the lowest point is 
His potential energy to his point would be:

This contraption is a lot of fun, and you really should try it
some time.
The sound waves move from one can to the other one
by traveling through the string.
The height of the rail on top of the press box where the ball was dropped from is 11.025 m.
The given parameters:
- Time of motion of the ball, t = 1.5 s
- Let the height of the rail = h
<h3>Maximum height of fall;</h3>
- The maximum height through which the ball was dropped from is calculated by applying second equation of motion;

Thus, the height of the rail on top of the press box where the ball was dropped from is 11.025 m.
Learn more about height of projectiles here: brainly.com/question/10008919
Answer;
-Mass
Explanation;
-An intensive property is a physical quantity whose value does not depend on the amount of the substance for which it is measured. For example, boiling point, density, color, melting point, Odor, temperature, etc.
-Extensive properties on the other hand, do depend on the amount of matter that is present. An extensive property is considered additive for subsystems. Examples of extensive properties include: volume, mass, size, weight. length, etc.