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3 years ago

Which of the statements below describes how a motor operates

Physics

1 answer:

uranmaximum [27]3 years ago

7 0

Answer:

need Read this excerpt from "Not a Dove, But No Longer a Hawk."

Despite these misgivings, I do not see how we can do anything but continue to prosecute the war. We can and should limit the violence and the suffering being inflicted on the civilians as much as possible, but for whatever reasons, successive Administrations in Washington have carried the commitment in Vietnam to the point where it would be very difficult to prevent any precipitate retreat from degenerating into a rout. If the United States were to disengage from Vietnam under adverse conditions, I believe that the resulting political and psychological shockwaves might undermine our entire position in Southeast Asia.

Which statement best describes the paradox in this excerpt?

The author acknowledges that civilians should not suffer, but states that the civilians must retreat.

The author suggests that the administrators in Washington are busy making policies while overlooking the need to end the war.

The author acknowledges that the violence should stop, but admits that a retreat might have dire consequences.

The author suggests that the Vietnamese people are counting on US support, though their political ideals are not democratic.

Explanation:

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A tightly sealed glass jar is an example of which type of system?

noname [10]

D. hope it helps. :D

4 0

3 years ago

Read 2 more answers

During a race, four competitors of the same weight rode identical bicycles for 10 minutes. At 8 minutes, which bicycle was movin

Sophie [7]

Answer:

All the competitors will move with the same velocity.

Explanation:

Here, the situations for each competitor are identical. Thus, they will exert the same force and hence, their velocities at each instants will be identical.

6 0

3 years ago

The best rebounders in basketball have a vertical leap (that is, the vertical movement of a fixed point on their body) of about

nadya68 [22]

Answer:

a) 4.45 m/s

b) 0.9 seconds

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration due to gravity = 9.81 m/s²

$v^2-u^2=2as\\\Rightarrow -u^2=2as-v^2\\\Rightarrow u=\sqrt{v^2-2as}\\\Rightarrow u=\sqrt{0^2-2\times -9.81\times 1}\\\Rightarrow u=4.45\ m/s$

a) The vertical speed when the player leaves the ground is 4.45 m/s

$v=u+at\\\Rightarrow t=\frac{v-u}{a}\\\Rightarrow t=\frac{0-4.45}{-9.81}\\\Rightarrow t=0.45\ s$

Time taken to reach the maximum height is 0.45 seconds

$s=ut+\frac{1}{2}at^2\\\Rightarrow 1=0t+\frac{1}{2}\times 9.81\times t^2\\\Rightarrow t=\sqrt{\frac{1\times 2}{9.81}}\\\Rightarrow t=0.45\ s$

Time taken to reach the ground from the maximum height is 0.45 seconds

b) Time the player stayed in the air is 0.45+0.45 = 0.9 seconds

6 0

3 years ago

If two people lift identical stacks of books the same distance and one person does the job twice as fast, which of the following

Doss [256]

Answer:

Power

Explanation:

Power is defined as the rate of doing work with reference to the time spent and the formula is force multiplied by velocity.

In this case, if two people lift identical stacks of books the same distance and one person does the job twice as fast, then it means the velocity in the case is doubled which will also lead to an increase in the Power .

7 0

3 years ago

Alcohol of mass 33.2g and density 0.79kg/m³ or 790kg/m³ is mixed with water of 9g. What is the density of the resulting mixture?

KATRIN_1 [288]

Answer:

0.83 g/cm³

Explanation:

The volume of the alcohol is ...

(33.2 g)/(0.79 g/cm³) ≈ 42.0253 cm³

The density of water is about 1 g/cm³, so the volume of 9 g of it is ...

(9 g)/(1 g/cm³) = 9 cm³

The total volume is ...

42.0253 cm³ +9 cm³ = 51.0253 cm³

The total mass is ...

33.2 g + 9 g = 42.4 g

So, the resulting density is ...

(42.4 g)/(51.0253 cm³) ≈ 0.83 g/cm³

The resulting mixture has a density of about 0.83 g/cm³.

_____

<em>Additional comment</em>

Alcohol dissolves in water, so the total volume will be slightly less than 51.0253 cm³. The attached curve shows the result of mixing ethanol and water.

The weight of a mole of ethanol is about 46 g, of water, about 18.02 g. Then the mole fraction of alcohol is ...

(33.2/46)/(33.2/46 +9/18.02) ≈ 0.59

The volume of the mix is then estimated to be (-1.05 cc/mol)(1.221 mol), or about 1.28 cm³ less than the volume indicated above. That brings the density up to about 0.85 g/cm³.

We're not completely sure of the relevance of this calculation, since many of the applicable parameters are not specified. The point is that <em>the density of the mix will probably be slightly more than the value calculated above</em>. YMMV

3 0

3 years ago