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2 years ago

Are the objects described here in static equilibrium, dynamic equilibrium, or not equilibrium at all? Explain.

2 answers:

4 0

Let us examine the given situations one at a time.

Case a. A 200-pound barbell is held over your head.
The barbell is in static equilibrium because it is not moving.
Answer: STATIC EQUILIBRIUM

Case b. A girder is being lifted at a constant speed by a crane.
The girder is moving, but not accelerating. It is in dynamic equilibrium.
Answer: DYNAMIC EQUILIBRIUM

Case c: A jet plane has reached its cruising speed at an altitude.
The plane is moving at cruising speed, but not accelerating. It is in dynamic equilibrium.
Answer: DYNAMIC EQUILIBRIUM

Case d: A box in the back of a truck doesn't slide as the truck stops.
The box does not slide because the frictional force between the box and the floor of the truck balances out the inertial force. The box is in static equilibrium.
Answer: STATIC EQUILIBRIUM

nordsb [41]2 years ago

4 0

Statement a and e are in static equilibrium, b and d are in dynamic equilibrium and c is not at equilibrium at all.

<h3>FURTHER EXPLANATION</h3>

When the net force acting on an object is zero, the object is said to be at equilibrium. The state of equilibrium can be classified into two: static and dynamic.

Static equilibrium is when the net force is zero resulting in the object being at rest or not moving.

Dynamic equilibrium is when the resultant force acting on an object is zero and the object is moving in a uniform motion (i.e. constant or unchanging speed).

A. a 200 pound barbell is held above your head

<em>Since the barbel is "held above your head" and is implied to be at rest since there is no change in its position during the time it is held, then this situation is an example of static equilibrium.</em>

B. A girder is being lifted at a constant speed by a crane

<em>This is dynamic equilibrium because the object is moving "at a constant speed".</em>

C. A girder is being lowered into place. It is slowing down.

<em>This is not equilibrium condition because the objects is neither at rest nor moving at a constant speed. It is "slowing down", so the speed is decreasing.</em>

D. A jet plane has reached its cruising speed and altitude.

<em>The "cruising speed" is the speed that is maintained while the jet plane is traveling because this is considered to be the most efficient speed. Since it is maintained, the jet plane is said to be in constant motion. Therefore, this is dynamic equilibrium.</em>

E. A box in the back of a truck doesn't slide as the truck stops.

<em>This is static equilibrium because the box is stationary or not moving.</em>

<em />

<h3>LEARN MORE</h3>

Balanced Forces brainly.com/question/1675020
Resultant Force brainly.com/question/7041906
Friction brainly.com/question/3401004

Keywords: equilibrium, static equilibrium, dynamic equilibrium

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Answer:

Using the new cylinder the heat rate between the reservoirs would be 50 W

Explanation:

Conduction could be described by the Law of Fourierin the form: $Q=kA\frac{T_1-T_2}{L}$ where $Q$ is the rate of heat transferred by conduction, $k$ is the thermal conductivity of the material, $T_1$ and $T_2$ are the temperatures of each heat deposit, $A$ is the cross area to the flow of heat, and ${L}$ is the distance that the flow of heat has to go.
For the original cylinder the Fourier's law would be: $kA_1\frac{T_1-T_2}{L_1}=25W$ , and if $A_1=\frac{\pi D_{1}^{2}}{4}$ , then the expression would be: $k\frac{\pi D_1^{2}}{4} \frac{T_1-T_2}{L_1}=25W$ where $D_1$ is the diameter of the original cylinder, and ${L_1}$ is the length of the original cylinder.
For the new cylinder, in the same fashion that for the first, Fourier's Law would be: $Q_2=k\frac{\pi D_2^2}{4}\frac{T_1-T_2}{L_2}$ ,where $Q_2$ is the heat rate in the second case, $D_2$ and ${L_2$ are the new diameter and length.
But, $D_2=2D_1$ and $L_2=2L_1$ , substituting in the expression for $Q_2$ : $Q_2=k\frac{\pi (2D_1)^2}{4}\frac{T_1-T_2}{2L_1}$ .
Rearranging: $Q_2=\frac{2^2}{2}(k\frac{\pi D_1^2}{4}\frac{T_1-T_2}{L_1})$ .
In the last declaration of $Q_2$ , it could be noted that the expressión inside the parenthesis is actually $Q_1$ , then: $Q_2=\frac{2^2}{2}(25W)=50W$ .
<u>It should be noted, that the temperatures in the hot and cold reservoirs never change.</u>

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2 years ago

Select the areas that would receive snowfall because of the lake effect.

Studentka2010 [4]

Answer:

- Grand Marais

- Two Harbors

- Duluth

Explanation:

The places that would would get snowfall because of the lake effect are Grand Marais, Two Harbors, and Duluth. The reason for this is that these three places are located right on the shores of the Lake Superior. This lake is one of the biggest lakes in the world. It has enormous amount of water in it, having big impact on the regional climate because of that. The water from this lake creates a lot of humidity in the air, and there's a lot of evaporation as well, both causing the formation of clouds, and when it is cold enough, instead of precipitation, the region gets large amounts of snowfall.

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2 years ago

The study of alternating electric current requires the solutions of equations of the form i equals Upper I Subscript max Baselin

KiRa [710]

Answer:

Explanation:

i = Imax sin2πft

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Put the give values in the equation above

180 = 200 sin 2πft

sin 2πft = .9

sin2π x 50t = .9

sin 360 x 50 t = sin ( 360n + 64 )

360 x 50 t = 360n + 64

360 x 50 t = 64 , ( putting n = 0 for least value of t )

18000 t = 64

t = 3.55 ms .

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2 years ago

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Potassium belongs to group IA of the elements. This means that it will give up one of its electrons to form the cation K+. Opposite to that is bromine in which it accepts one electrons to form the anion Br-. The binding of these elements will form KBr and is formed from transfer of electron from one element to the other. This is the mechanism of ionic bond formation.

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Answer:

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Explanation:

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