A 25.0 kg child slides down a long slide in a playground. She starts from rest at a height h1 of 21.00 m. When she is partway down the slide, at a height h2 of 8.00 m, she is moving at a speed of 7.80 m/s. Calculate the mechanical energy lost due to friction (as heat, etc.).

Answer:

Explanation:

since it is connected in parallel combination

use this formula

[tex]\frac{1}{R} = \frac{1}{R1} + \frac{1}{R2}[/tex]

[tex]\frac{1}{R} = \frac{1}{2} + \frac{1}{4}[/tex]

[tex]\frac{1}{R} = \frac{4+2}{2}[/tex]

[tex]\frac{1}{R} = \frac{6}{2}[/tex]

[tex]\frac{1}{R} = 3[/tex] ohm

therefore resistence = 3 ohm

then we should find power

P = VI

P = 12*3

P = 24 watt

now to find current use formula power = current * voltage

24 = current * 12

24/12 = current

2 = current

therefore current is 2 ampere (A).

to find potential difference (emf) use formula

V = IR

V = current * resistence

V = 2 * 3

V = 6 volt .

therefore potential difference is 6 volt.

1517.4 m

Step-by-step explanation:

Since the projectile broke up at the peak of its flight, it already traveled half its initial range so we can find its initial launch velocity [tex]v_0[/tex] from the equation

[tex]\frac{1}{2}R= \dfrac{1}{2} \left(\dfrac{v_0^2}{g}\sin 2\theta_0 \right)[/tex]

where [tex]\theta_0 = 45°[/tex] and [tex]\frac{1}{2}R = 50\:\text{m}[/tex] so we will get [tex]v_0=31.3\:\text{m/s}[/tex]. Next, we can use the equation

[tex]v_y = v_0y - gt = v_0 \sin 45 - gt[/tex]

and since [tex]v_y=0[/tex] at its peak, we get t = 22.1 s. Let's set this aside for a moment and we'll use it later.

At the top of its peak, we can use the conservation law of linear momentum. Let M be the mass if of the original projectile, [tex]m_1[/tex] be the mass of the larger fragment (2 kg) and [tex]m_2[/tex] be the mass of the smaller fragment (1 kg). We can write the conservation law as

[tex]Mv_0x = m_1V_1 + m_2V_2[/tex]

where [tex]V_1\:\text{and}\:V_2[/tex] are the velocities of the fragments immediately after the break up. But we also know that [tex]V_1=0[/tex] so the velocity of [tex]m_2[/tex] can be calculated from the conservation law as

[tex]Mv_0 \cos 45° = m_2V_2[/tex]

or

[tex]V_2 = \dfrac{M}{m_2}v_0 \cos 45° = 66.4\:\text{m/s}[/tex]

Now we can calculate the horizontal distance the smaller fragment traveled after the break up. Recall that the amount of time for it to go up is also the amount of time to get down so the horizontal distance x is

[tex]x = V_2 t = (66.4\:\text{m/s})(22.1\:\text{s})= 1467.4\:\text{m}[/tex]

Therefore, the total distance traveled from the launch point is

[tex]D = 50\:\text{m} + 1467.4\:\text{m}=1517.4\:\text{m}[/tex]

Answer:

Option b, cosine.

Explanation:

Below you can see an image that illustrates this situation.

Remember that for a triangle rectangle with a given angle θ, we have:

Cos(θ) = (adjacent cathetus)/(hypotenuse)

In the image, you can see a vector of magnitude M, and the angle θ defined between the vector and the positive y-axis.

In this case, the y-component is the adjacent cathetus and the hypotenuse is the magnitude of the vector.

Then we will have:

Cos(θ) = (adjacent cathetus)/(hypotenuse) = y/M

solving that for y, we get:

y = Cos(θ)*M

Then the y-component is the vector's magnitude multiplied by the cosine of the angle between the vector and the y-axis.

The correct option is b.

Answer:

(b) cosine

Explanation:

In a 2-dimensional Cartesian coordinate system, a vector has a x-component and/or a y-component. To get these components, the magnitude of the vector is resolved with respect to the x-axis and the y-axis by multiplying it (the magnitude) by some trigonometric function with respect to the angle between the vector and the x or y axis.

For example, given a vector A of magnitude A which makes an angle α with the x-axis and an angle β with the y-axis, the x and y components of the vector A can be found as follows;

i. x-component is given by [tex]A_{x}[/tex]

[tex]A_{x}[/tex] = A cos α (with respect to the angle between A and the x-axis)  or

[tex]A_{x}[/tex] = A sin β (with respect to the angle between A and the y-axis)

ii. y-component is given by [tex]A_{y}[/tex]

[tex]A_{y}[/tex] = A sin α (with respect to the angle between A and the x-axis)  or

[tex]A_{y}[/tex] = A cos β (with respect to the angle between A and the y-axis)

Therefore, the y-component of a vector in a 2-dimensional Cartesian coordinate is given by the product of the magnitude of the vector and the cosine of the angle between the vector and the y-axis.

Answer:

D) all of the above.

Explanation:

First polarises it, cahrging and discharging occurs at once.

A negatively charged balloon touching a wooden wall then from the given options option D is correct which is all of the above.

Charged matter experiences a force when it is exposed to an electromagnetic field due to the physical property of electric charge. Positive or negative charges can exist in an electric field (commonly carried by protons and electrons, respectively).

Contrary charges attract one another, while like charges repel one another. A neutral object is one that carries no net charge. Classical electrodynamics, the name given to an early understanding of how charged particles interact, is still accurate for issues that do not call for taking into account quantum phenomena.

In the first step it polarizes molecules in the wall, then charging and discharging in the wall will take place at once.

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Answer:

because density of iron is more than that of water but less then that of Mercury

hope it's helpful

Answer:

below

Explanation:

Part A) This engine works  per cycle is 254.9 J.

Part B) The thermal efficiency is  23.42%

The thermal efficiency of any heat engine is represented in percentage of heat energy converted into work.

For isothermal expansion, work done is

W₁ =nRT₁ x ln(V₂/V₁)

W₁ = 0.1 x 8.314 x 800 x ln(5000/3000)

W₁ = 339.8 J =Q₁

For isochoric cooling ,

W₂ =0

Q₂ =nCvdT = 0.1 x 3R/2 x (T₂-T₁)

Q₂ = -748.3 J

For isothermal compression,

W₃ =nRT₂ ln (V₄/V₃)

W₃  = 0.1 x 8.314 x 200 x ln(3000/5000)

W₃ = -84.9J

For isochoric heating

W₄ =0

Q₄ =nCvdT = 0.1 x 3R/2 x (800-200)

Q₄  = -748.3 J

Total work done in all the process W = W₁ +W₂ +W₃ +W₄

W =254.9 J

Thus, the work done is 254.9 J

Thermal efficiency = Work done/Heat taken

η = W/ Q₁ +Q₄

η = [254.9 / 339.8 +748.3 ] x 100 %

η = 0.2342 x 100 %

η = 23.42%

Thus, the thermal efficiency is 23.42%

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Answer:

B) True. By changing the length get a different period and with a graph you can find the best value of the gravity pull

Explanation:

The student is reacting a simple pendulum experiment where he can determine the value of the relationship of gravity with the expression

              T = 2π [tex]\sqrt{\frac{L}{g} }[/tex]

let's analyze each statement

A) False. The mass is not a paramer of the period expression

B) True. By changing the length get a different period and with a graph you can find the best value of the gravity pull

C) False. The angle while it is small does not influence the period

D) True. By changing the number of oscillations the period does not change, so you can get the value of the pull of gravity.

We can see that the expressions B and d are true, the most exact value is obtained using procedure B since the graphs allow to reduce the errors

Explanation:

The torque [tex]\tau[/tex] is given by

[tex]\tau=Fd = (65\:\text{lbs})(\frac{8}{12}\:\text{ft}) = 43.3\:\text{lbs-ft}[/tex]

The voltage across the element is = 240 V

I hope you understand....

Mark me as brainliest....

Thanks...

Answer:

Total probability = 3/8

Explanation:

Below is the calculation:

Number of molecules in the container = 3

The probability of one molecule in the left half, P = 3 / 2 = 1.5 or 1/2

The probability of second molecule in the left half, P1 = (3/4)

Total probability = P x P1

Total probability = (1/2) x (3/4)

Total probability = 3/8

Answer:

To produce a single sugar molecule a plant must use a molecule of water (H2O) and carbon dioxide (CO2) and sunlight. To get 4 molecules, you simple use 4 molecules of water and 4 molecules of carbon dioxide

1) (40 N) cos(30°) ≈ 34.6 N

2) (40 N) sin(30°) = 20 N

3) (65 kg) g = (65 kg) (9.80 m/s²) = 585 N

4) The net force on the sled acting in the vertical direction is made up of

• the sled's weight, 585 N, pointing downward

• the vertical component of the applied force, 20 N, pointing upward

• the normal force, with magnitude n, also pointing upward

The sled does not move up or down, so by Newton's second law,

∑ F = n + 20 N - 585 N = 0   ==>   n = 565 N

5) The net force in the horizontal direction consists of

• the horizontal component of the applied force, 34.6 N, acting in the direction the sled's movement (call this the positive direction)

• kinetic friction, with magnitude f, pointing in the opposite and negative direction

By Newton's second law,

∑ F = 34.6 N - f = 0   ==>   f ≈ 34.6 N

Now if µ is the coefficient of kinetic friction, then

f = µn   ==>   µ = f/n = (34.6 N) / (565 N) ≈ 0.0613

The component of the force is the effective part of that force in that direction.

The component of the force is the effective part of that force in that direction.

1) The horizontal component of a force = 40 N cos 30 degrees = 34.6 N

2) The vertical component of the force = 40 N sin 30 degrees = 20 N

3) The magnitude of the gravitational force = mg cos 30 degrees  = 65 Kg * 9.8 m/s^2 * cos 30 degrees = 551.7 N

4) The normal force = 551.7 N

5) The coefficient of friction = F/R =  40 N /551.7 N = 0.07

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Answer:

x = 4.45 * 10 ^22  Note. Technically, this should be rounded to 4.5 * 10^22. There are only 2 sig digits.

Explanation:

You have to assume that the coin is pure copper, which I doubt.  What a coin is actually made of  depends on when it was minted. But for the sake of this question, we'll assume coins are pure copper.

Copper has an atomic mass of 63.546 grams / mol

So 4.7 g of copper = 4.7 / 63.545 mol

We have 0.07396 mol of copper

1 mol of anything = 6.02 * 10^23 atoms (in this case).

0.07396 mol        = x

Cross Multiply

1 * x = 0.07396 * 6.02 * 10^23

x = 4.45 * 10 ^22  atoms of copper

Answer:

the correct answer is B

Explanation:

Let's propose the solution of the problem, for this we form a system formed by the two cars, so that the forces during the collision are internal, the momentum is conserved

instantly starts. Before the crash

         p₀ = M v +0

final instant. After the crash

        m_f = (M + M) v_f

the moment is preserved

        p₀ = p_f

        M v = 2 M v_f

        v_f = v / 2

let's look for kinetic energy

before the crash

       K₀ = ½ M v²

after the crash

       K_f = ½ 2M (v_f)²

       K_f = ½ 2M (v/2)²

       K_f = (½ M v²) ½

       K_f = K₀ / 2

therefore the correct answer is B

Answer:

Yes it will move and a= 4.19m/s^2

Explanation:

In order for the box to move it needs to overcome the maximum static friction force

Max Static Friction = μFn(normal force)

plug in givens

Max Static friction = 31.9226

Since 36.6>31.9226, the box will move

Mass= Wieght/g which is 45.8/9.8= 4.67kg

Fnet = Fapp-Fk

= 36.6-16.9918

=19.6082

=ma

Solve for a=4.19m/s^2

Answer:

hey. i dont know what you tryna say but if u replying to someone else, you should use the comments section. in that way you won't lose points.

Answer:

Sentences with many clauses and phrases are difficult to understand because the clauses and phrases typically _____.

modify other clauses and phrases in the sentence

refer to other sentences in the passage

make it hard to determine where the sentence ends

change the intended meaning of the sentence

Explanation:

Answer:

17280 J and 1080 J

Explanation:

Given :

R= 40 ohm

I=1.2A

t= 5 min=60×5=300 sec

Now,

Total energy can be calculated as:

[tex]E=I^{2} Rt\\E=(1.2)^{2} *40*300\\E=17280 J[/tex]

Now,

V=12V

R=40 Ohm

[tex]E=\frac{V^{2} }{R} *t\\E=\frac{(12)^{2} }{40} *300\\E=1080 J[/tex]

Total energy  is 17280 J and 1080 J

Answer:

3.86×10⁶ Newton/coulombs

Explaination:

Applying,

E = F/q....................... Equation 1

Where E = Electric Field, F  = Force, q = charge.

From the question,

Given: F = 5.4×10⁻¹ N, q = -1.4×10⁻⁷ coulombs

Substitute these values into equation 1

E = 5.4×10⁻¹/ -1.4×10⁻⁷

E = -3.86×10⁶ Newtons/coulombs

Hence the magnitude of the electric field created by the

negative test charge is 3.86×10⁶ Newton/coulombs

Answer:

x_f = 212.5m

Explanation:

t = (x_f-x_0)/(.5*(v_f-v_0))

t = (98.26m-0m)/(.5(0m/s-17m/s))

t = 11.56s

a = (v_f-v_0)/t

a = (0m/s-17m/s)/11.56s

a = -1.47m/s²

t = (v_f-v_0)/a

t = (0m/s-25m/s)/-1.47m/s²

t = 17s

x_f = x_0+(.5*(v_f-v_0))*t

x_f = 0m+(.5*(0m/s-25m/s))*17s

x_f = 212.5m

Answer:

below

Explanation:

Answer:

His height is 6.66 feet or 79.92 inches.

Explanation:

Given that,

An AAMU basketball player is 2.03 meters tall.

Let h is the height.

We know that,

1 m = 3.28 feet

So,

2.03 m = 6.66 feet

Also,

1 m = 39.37 inches

2.03 m = 79.92 inches

Hence, this is the required solution.

Answer:

450N

Explanation:

weight= m*g

weight=45*10

weight=450N

Answer:

The heat source for our planet is the sun. Energy from the sun is transferred through space and through the earth's atmosphere to the earth's surface. Since this energy warms the earth's surface and atmosphere, some of it is or becomes heat energy.

Answer:

stress = 1.225 x 10^8 N/m^2

strain = 1/5

Young's modulus = 6.125 x 10^8 N/m^2

Explanation:

mass, m = 500 kg

length, L = 5 m

Area, A = 0.4 x 10^-4 m^2

Final length, L' = 6 m

extension, x = L'-L= 6 - 5 = 1 m

Stress is defined as force per unit area.

[tex]stress =\frac{Force}{Area}\\\\stress =\frac{500\times 9.8}{0.4\times 10^{-4}}\\\\stress = 1.225\times 10^8 N/m^2[/tex]

Strain is defined as the ratio of change in length to the original length.

[tex]strain =\frac{x}{L}\\\\strain = \frac{1}{5}[/tex]

Young's modulus is given by the ratio of stress to the strain.

[tex]Y = \frac{1.225 \times 10^8}{\frac{1}{5}}\\\\Y = 6.125\times 10^8 N/m^2[/tex]

Answer:

B = 4.51×10⁻⁵ T

Explanation:

Given that,

The average magnetic field strength of the Earth is 0.0000451 T.

We need to write the value in the form of scientific notation. Any number in scientific notation is written as follows :

N=a×bⁿ

Where

n is any integer and a is a real no

So,

0.0000451 = 4.51×10⁻⁵ T

So, the required answer is equal to 4.51×10⁻⁵ T.

Answer:

a because it is at a given moment

Explanation:

did u

Answer:

jsgssbvwsvs

Explanation:

ifmd understand

Answer:

2.86×10⁻¹⁸ seconds

Explanation:

Applying,

P = VI................ Equation 1

Where P = Power, V = Voltage, I = Current.

make I the subject of the equation

I = P/V................ Equation 2

From the question,

Given: P = 0.414 W, V = 1.50 V

Substitute into equation 2

I = 0.414/1.50

I = 0.276 A

Also,

Q = It............... Equation 3

Where Q = amount of charge, t = time

make t the subject of the equation

t = Q/I.................. Equation 4

From the question,

4.931020 electrons has a charge of (4.931020×1.6020×10⁻¹⁹) coulombs

Q = 7.899×10⁻¹⁹ C

Substitute these value into equation 4

t =  7.899×10⁻¹⁹/0.276

t = 2.86×10⁻¹⁸ seconds