11. B
12. A
13. D
14. The ball burnt off energy while rolling, it lost potential energy and couldn't go as high.
The answer should be B. Fault.
Explanation :
Simple machines makes our work easier. Lever is one of the simple machine which consists of rigid rod that is pivoted at a fixed support called as Fulcrum.
There are three classes of lever.
Class 1 : In this type of class, fulcrum is placed in between effort and load. Hence the movement of load is in reverse direction of the movement of effort. (fig 1)
Class 2 : In this type of, the load is between the effort and the fulcrum. Hence, the movement of load is in same direction as that of the effort. (fig 2)
Class 3 : In this type of lever the effort between the load and the fulcrum. Hence, both the effort and load are in same direction. (fig 3)
Hence, when the position of fulcrum is modified the effort force changes.
Answer:
0.702 m
Explanation:
The magnitude of the electrostatic force between two charged objects is given by Coulomb's Law:

where
k is the Coulomb's constant
q1, q2 are the two charges
r is the separation between the objects
And the force is:
- Attractive if the two charges have opposite signs (+-)
- Repulsive if the two charges have same sign (++ or --)
In this problem we have:
is the force between the two balls
is the charge on each ball
Solving for r, we find the separation between the balls:

I think it is building and managing of irrigation systems