Please show your workmkmmkekdmnesnndndndndn

Answer:

Explanation:

F = ma

Assuming the 20° is angle θ measured to the horizontal

mgsinθ - μmgcosθ = ma

g(sinθ - μcosθ) = a

at constant velocity, a = 0

g(sinθ - μcosθ) = 0

   sinθ - μcosθ = 0

                 sinθ = μcosθ

μ = sinθ/cosθ

μ = tanθ

μ = tan20

μ = 0.3639702342...

μ = 0.36

An Excerpt from “Optimism”

by Helen Keller

1 Could we choose our environment, and were desire in human undertakings synonymous with

endowment, all men would, I suppose, be optimists. Certainly most of us regard happiness as

the proper end of all earthly enterprise. The will to be happy animates alike the philosopher, the

prince and the chimney-sweep. No matter how dull, or how mean, or how wise a man is, he feels

that happiness is his indisputable right.

2 It is curious to observe what different ideals of happiness people cherish, and in what singular

places they look for this well-spring of their life. Many look for it in the hoarding of riches, some

in the pride of power, and others in the achievements of art and literature; a few seek it in the

exploration of their own minds, or in the search for knowledge.

3 Most people measure their happiness in terms of physical pleasure and material possession.

Could they win some visible goal which they have set on the horizon, how happy they would be!

Lacking this gift or that circumstance, they would be miserable. If happiness is to be so

measured, I who cannot hear or see have every reason to sit in a corner with folded hands and

weep. If I am happy in spite of my deprivations, if my happiness is so deep that it is a faith, so

thoughtful that it becomes a philosophy of life,—if, in short, I am an optimist, my testimony to

the creed of optimism is worth hearing....

4 Once I knew the depth where no hope was, and darkness lay on the face of all things. Then

love came and set my soul free. Once I knew only darkness and stillness. Now I know hope and

joy. Once I fretted and beat myself against the wall that shut me in. Now I rejoice in the

consciousness that I can think, act and attain heaven. My life was without past or future; death,

the pessimist would say, “a consummation devoutly to be wished.” But a little word from the

fingers of another fell into my hand that clutched at emptiness, and my heart leaped to the

rapture of living. Night fled before the day of thought, and love and joy and hope came up in a

passion of obedience to knowledge. Can anyone who has escaped such captivity, who has felt

the thrill and glory of freedom, be a pessimist?

5 My early experience was thus a leap from bad to good. If I tried, I could not check the

momentum of my first leap out of the dark; to move breast forward is a habit learned suddenly

at that first moment of release and rush into the light. With the first word I used intelligently, I

learned to live, to think, to hope. Darkness cannot shut me in again. I have had a glimpse of the

shore, and can now live by the hope of reaching it.

6 So my optimism is no mild and unreasoning satisfaction. A poet once said I must be happy

because I did not see the bare, cold present, but lived in a beautiful dream. I do live in a

beautiful dream; but that dream is the actual, the present,—not cold, but warm; not bare, but

furnished with a thousand blessings. The very evil which the poet supposed would be a cruel

6) Read the last sentence from the text.

Only by contact with evil could I have learned to feel by contrast the beauty of truth and love and goodness.

Explain how Helen Keller develops this idea in the text. Use specific details to

support your answer.

Enzymes. ... This is because heat energy causes more collisions, with more energy, between the enzyme molecules and other molecules. However, if the temperature gets too high, the enzyme is denatured and stops working. A common error in exams is to write that enzymes are killed at high temperatures.

Answer:

b

Explanation:

hope helpful

have a great day

Answer:

The brain is a part of the body that is particularly sensitive to high temperature. Hence some ungulates, like the Thomson's gazelle, use a counter-current heat exchanging structure known as the carotid rete to keep the brain cooler than the body.The cooled arterial blood then continues toward the brain.

Answer:

False

Explanation:

this is the correct answer

Answer:

C) 800

Explanation:

Answer:

60°

Explanation:

It will be equilateral triangle, you can prove with the cosine theorem.

1)P^2=P^2+P^2 - 2×P×P× cos A

2) cos A= P^2 / 2× P^2 = 1/2

cos A = 1/2

A = 60°

If you wrote this question right,it will be solved like this :)

Answer:

A

Explanation:

all galaxies exploded in order to create the sun/stars

Answer:

1. A. 0.4 kg

2. B. A team of players in tug of war pulling on the rope, each team with equal numbers of people pulling with equal strength

3.  If an object is stationary the net force is zero.

3. B. The force of friction on the object is different if it is stationary or not

Explanation:

2. If two tug of war teams were pulling with the same force, neither team would move the rope would be at a stand still.

Answer:

The above person to the right is correct except for Number 2. The answer for that will be a.

Explanation:

Remember that equal is a big hint that the scenario is balanced forces since all forces are canceling out thus the object doesn't move. In a. two people are pulling a wheel barrel on the same side. This means one side has more force than the other hence the wheel barrel moves.

The angular acceleration of the larger camshaft is 995.72 rad/s².

The given parameters;

The angular acceleration of the 3.75 cm camshaft is calculated as follows;

[tex]\omega _f = \omega _i + \alpha t\\\\\omega _f =0 + \alpha t\\\\\omega _f = \alpha t\\\\(1250 \ \frac{rev}{\min} \times \frac{2 \pi \ rad}{rev} \times \frac{1\min}{60 \ s} ) = 0.032 \alpha \\\\130.92 = 0.032\alpha \\\\\alpha = \frac{130.92}{0.032} = 4091.25 \ rad/s^2[/tex]

The angular momentum of the camshaft is calculated as follows;

[tex]I_1 \alpha _1 = I_2 \alpha_2 \\\\\frac{1}{2} mr_1^2 \alpha _1 = \frac{1}{2}m R^2 \alpha_2\\\\r_1^2 \alpha _1 = R^2 \alpha_2\\\\\alpha_2 = \frac{r_1^2 \alpha _1 }{R^2} \\\\\alpha_2 =\frac{(0.037)^2 \times (4091.25)}{(0.075)^2} \\\\\alpha _2 = 995.72 \ rad/s^2[/tex]

Thus, the angular acceleration of the larger camshaft is 995.72 rad/s².

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In order to calculate frictional force look below..

The formula given by

[tex]\\ \sf\longmapsto F_f=\mu N[/tex]

Or

[tex]\\ \sf\longmapsto F_f=\mu mg[/tex]

u is coefficient of friction

N is normal reaction.

The force that will move the box at constant velocity must be a little more than 64 N.

The coefficient of sliding friction is obtained from the formula;

μ= F/R

Where;

F = frictional force

μ = coefficient of sliding friction

R = Normal reaction

It is necessary to note that the force that will move the body must be greater than the frictional force acting between the body and the surface in order to move the body. Hence, the force that will move the box at constant velocity must be a little more than 64 N.

Learn more: https://brainly.com/question/11969651

Answer:

bowling ball, basket ball, tennis ball

Explanation:

Answer:

0 because she went to exact same place as before

Answer:

tan 249 = 2.61

tan 249 = tan (249 - 180) = tan 69 = 2.61

Answer:

A syncline is visible.

Explanation:

A syncline is visible.

Answer:

These mountains show no evidence of folding.

Focus on the ball. Do you see you? Keep following it. Put all your energy into watching it and then unlock your third eye. With that you'll be able to determine your question.

Answer:

c

Explanation:

Answer:

Explanation:

Your question is quite confusing, particularly the information about microsecond = 0.5.

I'm going to ASSUME that you mean coefficient of static friction μs = 0.5

unfortunately typing a subscript "s" is very difficult and probably leads to such confusion.

I will also ASSUME that the block, and spring, and force vector are all horizontal.

If the force is slowly increased until the block slips, the spring will compress until the force on each end equals the maximum static friction force. As we are not concerned with the compression distance, only the force, we can ignore the spring constant information and simply find the maximum available static friction force.

F = μN

F = μmg

F = 0.5(4.0)(9.8)

F = 19.6 N

Not that it matters, but the spring will have extended or compressed 19.6/0.8 = 24.5 m, which is a very long and very light spring

Explanation:

nnnnkgcbchg of bbjbjk oh jjzjjzkedkkdkfjjsjdsjfkjfdkkdowkronqfojofj see j FC

Answer:

include the statements pls so i can choose wich one it is and tell you

Explanation:

Answer:

The elastic limit of a material is the furthest

point it can be stretched or deformed while

being able to return to its previous shape.

Explanation:

Once a material has gone past its elastic

limit, its deformation is said to be inelastic.

The higher the spring constant, the stiffer

the spring.

Answer:

C, B, and D are ones i think i know that can occur during a physical change

Explanation:

Explanation: Solution

1.

Gravitational potential energy

U=mgh=500*9.8*50

U=245000 J

2.

Kinetic energy is present at bottom of the hill

K=(1/2)mV2=(1/2)*500*27.82

K=193210 J

3.

Work done by friction

W=193210-245000=-51790 J

The mechanical energy at the top and bottom of the hill is equal to 352800 J and 163840 J respectively.

Kinetic energy (KE) can be described as the energy possessed by a moving object due to its motion. Work by a body will be done to change the kinetic energy. The kinetic energy is represented as K.E = ½mv².

Potential energy (P.E) can be described as the energy that is stored by an object due to its position and is represented in the equation as P.E = mgh, where ‘m’ is the mass, ‘g’ is the acceleration due to gravity and ‘h’ is the height.

The mechanical energy = Kinetic energy + potential energy

Given, the mass of the car, m = 500 Kg

The height of the hill, h = 72 m

The velocity of the car, v = 25.6 m/s

At the top of the hill, the mechanical energy = potential energy

The potential energy at the top of the hill, = mgh

P. E. = 500 × 9.8 ×72

P.E. = 352800 J

At the bottom of the hill, the mechanical energy = kinetic energy

The kinetic energy of the car at the bottom of the hill,

K.E. =  ½ × 500 (25.6)²

K.E. = 163840 J

Learn more about kinetic energy and potential energy, here:

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Answer:

I'm not sure in which direction 10kg is lifted but assuming 10kg is lifted (or dragged) horizontally then

the 20kg vertically requires more work because gravity pushing down on it will require a somewhat large output of Energy.

But if they are both lifted vertically (or horizontally)then they are equal in work.

Hope this helps