(a) The stress in the post is 1,568,000 N/m²
(b) The strain in the post is 7.61 x 10⁻⁶
(c) The change in the post’s length when the load is applied is 1.9 x 10⁻⁵ m.
<h3>Area of the steel post</h3>
A = πd²/4
where;
d is the diameter
A = π(0.25²)/4 = 0.05 m²
<h3>Stress on the steel post</h3>
σ = F/A
σ = mg/A
where;
- m is mass supported by the steel
- g is acceleration due to gravity
- A is the area of the steel post
σ = (8000 x 9.8)/(0.05)
σ = 1,568,000 N/m²
<h3>Strain of the post</h3>
E = stress / strain
where;
- E is Young's modulus of steel = 206 Gpa
strain = stress/E
strain = (1,568,000) / (206 x 10⁹)
strain = 7.61 x 10⁻⁶
<h3>Change in length of the steel post</h3>
strain = ΔL/L
where;
- ΔL is change in length
- L is original length
ΔL = 7.61 x 10⁻⁶ x 2.5
ΔL = 1.9 x 10⁻⁵ m
Learn more about Young's modulus of steel here: brainly.com/question/14772333
#SPJ1
Claim 2: Molecules speed up when they get energy from other molecules and slow down when they give energy to other molecules.
Energy can’t be destroyed (stated in claim 1) so claim 2 is more than likely to be correct
<h2>Hello!</h2>
The answer is: B. Kinetic energy
<h2>
Why?</h2>
Since the ball is falling, speed increases because the gravity acceleration is acting. When speed increases, the kinetic energy increases too, so the ball is gaining kinetic energy.
The gravity acceleration is equal to 
, it means that when falling, the ball will increase it's speed 9.81m every second.
We can calculate the kinetic energy by using the following formula:
Where:
Have a nice day!
<h2 />
Answer:
Explanation:
Given that the airplane starts from the rest (this is initial velocity equals to zero) and accelerates at a constant rate, position can be described like this: 
where x is the position, t is the time a is the acceleration and 
is initial velocity. In this way acceleration can be found. 
.
Now we are able to found velocity at any time with the formula: 
