I think the best answer would be the last option. The main purpose of a service panel in a house is to keep electrical hazards localized. Service panels are used to identify circuit loads and isolate these loads so when you want to check the equipment you can easily identify the line. Also, it would serve as the isolation point to avoid any electrical hazards.
Answer:

Explanation:
Let the height of the ladder be L

Also:
- Let

- Let

When the ladder leans against the wall, it forms a triangle and the length of the ladder forms the hypotenuse.
So, we have:
--- Pythagoras Theorem
When the base is 9ft from the wall, this means that:

Substitute 9 for x and 10 for L in 


Make
the subject


Make y the subject


<em>Hence, the true distance at that point is approximately 4.36ft</em>
The velocity of the cannonball is 150 m/s, the right option is B. 150 m/s.
The question can be solved, using Newton's second law of motion.
Note: Momentum of the cannon = momentum of the cannonball.
<h3>
Formula:</h3>
- MV = mv................. Equation 1
<h3>Where:</h3>
- M = mass of the cannon
- m = mass of the cannonball
- V = velocity of the cannon
- v = velocity of the cannonball
Make v the subject of the equation.
- v = MV/m................ Equation 2
From the question,
<h3>Given: </h3>
- M = 500 kg
- V = 3 m/s
- m = 10 kg.
Substitute these values into equation 2.
- v = (500×3)/10
- v = 150 m/s.
Hence, The velocity of the cannonball is 150 m/s, the right option is B. 150 m/s.
Learn more about Newton's second law here: brainly.com/question/25545050
The Hooke's law is a principal of physics that states that the force needed to extend or compress a spring by some distance x scales linearly with respect to that distance.