Answer:
<h3>since erosion is unavoidable the problem becomes discovering ways to prevent it. present beach erosion prevention methods include sand bags,vegetation,seawalls,sand dunes,and sand fences.</h3>
Answer:
A) 
= 77.6 ⁰C
, B) = 341.6 C
Explanation:
The thermal expansion is given by
ΔL = α L₀ ΔT
The thermal expansion coefficient for polycarbonate varies between 65 and 70 10⁻⁶ ⁰C⁻¹ and for cast iron 12 10⁻⁶ C⁻¹
Let's look for the final temperature that says same shift change
ΔT = ΔL / α L₀
- T₀ = ΔL /α L₀
= T₀ + ΔL / α L₀
Let's calculate for each material
A) Polycarbonate use as thermal expansion coefficient 70 10⁻⁶ C⁻¹
= 23.0 + 0.0268 / (70 10⁻⁶ 7.01)
= 23.0 + 54.6
= 77.6 ⁰C
B) cast iron with thermal expansion coefficient 12 10⁻⁶ C⁻¹
= 23.0 + 0.0268 / (12 10⁻⁶ 7.01)
= 23.0 + 3.1859 10²
= 341.6 C
Answer: The correct statements are:
- The atoms are very attracted to one another.
- The atoms are held tightly together.
Explanation:
Solid state: In this state, the molecules are closely packed and cannot move freely from one place to another that means no space between them and the intermolecular force of attraction between the molecules are strong.
In solid substance, the particles are very close to each other due to this the intermolecular forces of attraction are strongest.
The key point about solid are:
- The atoms are very attracted to one another.
- The atoms are not moving freely.
- It will not spread out evenly to fill any container.
- The atoms are held tightly together.
- The forces of attraction are strong to bring molecules together.
- The atoms are close and in fixed positions.
Answer: D. 40
Explanation:
Power = Force * Velocity
Force = 600N
Power needs to be converted to Watts:
= 24 * 1,000
= 24,000 W
24,000 = 600 * Velocity
Velocity = 24,000/600
= 40 m/s
You can tell if vector is an unit because it has something to do with taking the magnitude of the vector.
also has a length 1. thus you should use pythagoras to check.
Hope this help
