A train travels from Boston to New York. It travels at a speed of 180 km/h for two hours, speeds up to 200 km/h for the next four hours and then slows down to 120 km/h for the next six hours. What is the average speed of the train for this trip?

Answer:

A

Explanation:

Answer: B

Explanation: I got it right

Answer:

resistance = (resistivity.(l/A))

so for the 2 materials we get

r1 = resistivity.(l/r)

r2=resistivity.(2l/(r/2))

so ratio r1/r2=1/4

Explanation:

The resistance is proportional to the length and inversely proportional to the area (which is proportional to the square of the radius). Thus if we are just comparing the two (so the constants will cancel out).

r1 = l/r^2 (r squared).

r2 = (2l)/(1/2r)^2

r2 = 2l/(1/4)r^2

dividing by 1/4 is the same as multiplying to 4, so you are multiplying by 2 and then by 4, thus by 8.

Thus R2 is 8 times more than R1.

Answer:

the conclusion is that the plant that had been given fertilizer B grew more than the plant with fertilizer A and the plant without fertilizer. so in conclusion fertilizer B is better for growing plants fastly.

the problem is that you noticed your tomatoes were not growing properly.

Hope this helps!❤

Answer:

A) aₓ = -0.717 m / s² ,  B)  a_{y} = -1.024 m / s², C) x = 11.77 m , D) y = -4.6 m ,

E)  d = 12.64 m

Explanation:

For this exercise we will use trigonometry to decompose the acceleration, we are told that

   a = 1.25 m /s²   with an angle tea = 125º in a clockwise direction

A) cos θ = aₓ / a

       aₓ = a cos θ

       aₓ = 1.25 cos (-125)

       aₓ = -0.717 m / s²

B)  sin θ = [tex]a_{y}[/tex] / a

     a_{y} = a sin θ

     a_{y} = 1.25 sin (-125)

    a_{y} = -1.024 m / s²

C) The displacement component

     x = v₀ₓ t + ½ aₓ t²

let's calculate

      x = 5 3 + ½ (-0.717) 3²

      x = 11.77 m

D) the y component of the displacement

      y = [tex]v_{oy}[/tex] t + ½ [tex]a_{y}[/tex] t²

in this case the initial velocity is zero

      y = 0 + ½ (-1,024) 3²

      y = -4.6 m

E) Let's use the Pythagorean theorem

     d =√ (x² + y²)

     d = √ (11.77² + 4.6²)

     d = 12.64 m

9514 1404 393

Answer:

  Mona

Explanation:

Speed is the slope of the position vs. time curve. The higher speed will have the greater slope.

Mona's curve has a greater slope, so Mona is fastest.

Answer:

i had this question as well!

Explanation:

Answer:

1. to the Mystic 2. A Theme or social value 3. Something that can be valued 4. Can’t be observed/ Noticed.

Explanation:

Answer:

2.405 m/s

Explanation:

Given that,

Mass of a women, m₁ = 60 kg

Mass of a ball, m₂ = 3.9 kg

Velocity of the ball, v₂ = 37 m/s

We need to find the velocity of the woman. It is a concept based on the conservation of linear momentum. Let v₁ is the velocity of the woman. So,

[tex]m_1v_1=m_2v_2\\\\v_1=\dfrac{m_2v_2}{m_1}\\\\v_1=\dfrac{3.9\times 37}{60}\\\\v_1=2.405\ m/s[/tex]

So, the velocity of the woman is 2.405 m/s.

Answer:

Stated below:

Explanation:

Let's calculate the maximum height

.

H=v^2/2g=320mH=v  

2

/2g=320m

PE=mgh=0.1*10*320=320 J

at halfway up PE will be half of max = 320/2=160 J

KE will be equal to PEmax=320 J.

Hope I helped! ☺

Answer:

"When face is placed between the concave mirror and its focus, it produces a magnified image. This enlarged image of face is helpful in makeup as even pores of skin are clearly visible."

Answer:

R∠          is  152,3 ∠ 246,8

Explanation:

We need to add (vectorially)  these two velocities. We can choose the coordinates system just that speed of the airplane is the negative part of the y-axis, and negative region of the x-axis, for wind speed, according to

this, the module of the resultant velocity R is:

R =√ (60)² + (140)²

R = √( 3600) + ( 19600)

R =√ 23200

R = 152,315 mph

The tangent of the angle (α )  between R and the y-axis is:

tan α = 60/140

tan α = 0,4286

From tangent tables, we get arctan 0.4286  

α = 23,2⁰

Then R∠    is  152,3 ∠ 246,8

Answer:

R∠          is  152,3 ∠ 246,8

Answer:

The value is  [tex]\lambda  = 214.3  \ nm [/tex]

Explanation:

From the question we are told that

   The  slit separation is  [tex]d =  3.00 * 10^{-5} m[/tex]

    The  distance of the screen is  [tex]D =   2.00\ m[/tex]

    The  order of fringe is  n  =  7

    The path difference is  [tex]y =  10.0 \ cm  =  0.1 \  m[/tex]

    Generally the path difference is mathematically represented as

      [tex]y =  \frac{n *  \lambda  *  D}{ d}[/tex]

=>   [tex]0.1 =  \frac{7 *  \lambda  * 2.00 }{ 3.00 * 10^{-5}}[/tex]

=>  [tex]\lambda  =  \frac{0.1 *3.00 * 10^{-5} }{7 * 2.00 }[/tex]

=>   [tex]\lambda  =  \frac{0.1 *3.00 * 10^{-5} }{7 * 2.00 }[/tex]

=>   [tex]\lambda  = 2.143 *10^{-7} \  m [/tex]    

=>    [tex]\lambda  = 214.3  \ nm [/tex]

Answer:

The amount of net force of the falling object is -310 N, or 310 N downwards

Explanation:

Net Force

Being the force a vector, the net force is the sum of all the force vectors acting on an object at a given time:

[tex]\vec F_n=\vec F_1+\vec F_2+\vec F_3+.....\vec F_m[/tex]

When the forces are acting in one axis, say the y-axis, the direction of the forces can be considered by the sign of the magnitude of the force.

For example, the weight of the object is usually assigned a negative direction. In our problem:

W=-744 N

The air resistance always opposes the direction of motion. Since the object is falling, the air resistance is positive:

Fa = +434 N

The net force is the sum of both, including their signs:

Fn = -744 N + 434 N = -310 N

The amount of net force of the falling object is -310 N, or 310 N downwards

Answer:

Your accleration would be 3.2 seconds because it takes you that long to reach 35 miles per hour.

Explanation:

I really hopes this helps.

Answer:

31.25m

Explanation:

Given parameters:

   Acceleration due to gravity  = 10m/s²

    Time of drop = 2.5s

Unknown

Height of drop  = ?

Solution:

To solve this problem, we must note that the brick was originally at rest. The appropriate motion equation to solve this is shown below;

          H  = ut + [tex]\frac{1}{2}[/tex]gt²

H is the height

u is the initial velocity

g is the acceleration due to gravity

t is the time taken

          Input the parameters and solve;

      H = 0 +  [tex]\frac{1}{2}[/tex] x 10 x 2.5²

     H = 31.25m

Explanation:

1) N₂ + O₂ → 2 NO

Kc = [NO]² / ([N₂] [O₂])

Set up an ICE table:

[tex]\left[\begin{array}{cccc}&Initial&Change&Equilibrium\\N_{2}&0.114&-x&0.114-x\\O_{2}&0.114&-x&0.114-x\\NO&0&+2x&2x\end{array}\right][/tex]

Plug into the equilibrium equation and solve for x.

1.00×10⁻⁵ = (2x)² / ((0.114 − x) (0.114 − x))

1.00×10⁻⁵ = (2x)² / (0.114 − x)²

√(1.00×10⁻⁵) = 2x / (0.114 − x)

0.00316 = 2x / (0.114 − x)

0.00361 − 0.00316x = 2x

0.00361 = 2.00316x

x = 0.00018

The volume is 1.00 L, so the concentrations at equilibrium are:

[N₂] = 0.114 − x = 0.11382

[O₂] = 0.114 − x = 0.11382

[NO] = 2x = 0.00036

2(a) Cl₂ → 2 Cl

Kc = [Cl]² / [Cl₂]

[tex]\left[\begin{array}{cccc}&Initial&Change&Equilibrium\\Cl_{2}&2.0&-x&2.0-x\\Cl&0&+2x&2x\end{array}\right][/tex]

1.2×10⁻⁷ = (2x)² / (2 − x)

1.2×10⁻⁷ (2 − x) = 4x²

2.4×10⁻⁷ − 1.2×10⁻⁷ x = 4x²

2.4×10⁻⁷ ≈ 4x²

x² ≈ 6×10⁻⁸

x ≈ 0.000245

2x ≈ 0.00049

2(b) F₂ → 2 F

Kc = [F]² / [F₂]

[tex]\left[\begin{array}{cccc}&Initial&Change&Equilibrium\\F_{2}&2.0&-x&2.0-x\\F&0&+2x&2x\end{array}\right][/tex]

1.2×10⁻⁴ = (2x)² / (2 − x)

1.2×10⁻⁴ (2 − x) = 4x²

2.4×10⁻⁴ − 1.2×10⁻⁴ x = 4x²

2.4×10⁻⁴ ≈ 4x²

x² ≈ 6×10⁻⁵

x ≈ 0.00775

2x ≈ 0.0155

F₂ dissociates more, so Cl₂ is more stable at 1000 K.

Answer:

I have no clue what this means or what the answer is i am just trying to get my points up so i can ask questions

Explanation:

i am going to put something here so it looks like an explanation so yeah this has no meaning whatsoever i am very sorry that i am not able to give you the answer try looking the answer up im very very very very sorry :(

Answer:

Yes, eating chocolate causes pimples.. usually on your forehead

Explanation:

Chocolate may increase the severity and frequency of acne breakouts by encouraging the immune system to react more aggressively to the two bacteria that cause acne, aka pimples  [found this image on internet]

Answer:

The idea that population growth is potentially exponential while the growth of the food supply or other resources is linear.

Explanation:

Answer:

An object's inertia tends to resist any change in its state of rest or motion. If a carpet is beaten with a stick then the carpet begins to move. But, the particles of dust are trying to resist their state of rest.

Answer:

The answer is 4, the west.

Answer:

The west

Explanation:

hopes this helps you and your questions

Answer:

neutron beta particle and proton (last option in the list)

Explanation:

The neutron beta particle and proton inside a neutron is a clear example of a negative particle (beta particle) and a positive particle (proton) experiencing electromagnetic force (attraction between positive and negative charges) at a very short distance.

Answer:

I'm pretty sure it's the flashlight because electromagnetic force produces electricity.

Answer:

a) The average force that acts on the man is [tex]2.508\times 10^{8}[/tex] newtons.

b) The average force that acts on the man is 1023.673 newtons.

c) The force of the ground on the man is 1612.093 newtons upwards.

Explanation:

a) After a careful reading of the statement we construct the following model by applying Impact Theorem, that is:

[tex]m\cdot \vec v_{A} + \vec F \cdot \Delta t = m\cdot \vec v_{B}[/tex] (Eq. 1)

Where:

[tex]m[/tex] - Mass of the man, measured in kilograms.

[tex]\vec v_{A}[/tex] - Initial velocity of the man, measured in meters per second.

[tex]\vec v_{B}[/tex] - Final velocity of the man, measured in meters per second.

[tex]\Delta t[/tex] - Impact time, measured in seconds.

[tex]\vec F[/tex] - Average net force, measured in newtons.

Now we proceed to clear average net force within expression:

[tex]\vec F \cdot \Delta t = m\cdot (\vec v_{B}-\vec v_{A})[/tex]

[tex]\vec F = \frac{m}{\Delta t}\cdot (\vec v_{B}-\vec v_{A})[/tex] (Eq. 2)

If we know that [tex]m = 60\,kg[/tex], [tex]\vec v_{A} = -4.18\,\hat{j}\,\,\,\left[\frac{m}{s} \right][/tex], [tex]\vec v_{B} = 0\,\hat{j}\,\,\,\left[\frac{m}{s} \right][/tex] and [tex]\Delta t = 1\times 10^{-6}\,s[/tex], we obtain the following vector:

[tex]\vec F = \frac{60\,kg}{1\times 10^{-6}\,s} \cdot (4.18\,\hat{j})\,\,\,\left[\frac{m}{s} \right][/tex]

[tex]\vec F = 2.508\times 10^{8}\,\hat{j}\,\,\,[N][/tex]

The average force that acts on the man is [tex]2.508\times 10^{8}[/tex] newtons.

(b) If we know that  [tex]m = 60\,kg[/tex], [tex]\vec v_{A} = -4.18\,\hat{j}\,\,\,\left[\frac{m}{s} \right][/tex], [tex]\vec v_{B} = 0\,\hat{j}\,\,\,\left[\frac{m}{s} \right][/tex] and [tex]\Delta t = 0.245\,s[/tex], we obtain the following vector:

[tex]\vec F = \frac{60\,kg}{0.245\,s} \cdot (4.18\,\hat{j})\,\,\,\left[\frac{m}{s} \right][/tex]

[tex]\vec F = 1023.673\,\hat{j}\,\,\,\left[N\right][/tex]

The average force that acts on the man is 1023.673 newtons.

(c) From Second Newton's Law we find the following equation of equilibrium:

[tex]\vec F = \vec N -\vec W[/tex] (Eq. 3)

Where:

[tex]\vec F[/tex] - Average force that acts on the man, measured in newtons.

[tex]\vec N[/tex] - Force of the ground on the man, measured in newtons.

[tex]\vec W[/tex] - Weight of the man, measured in newtons.

By applying the concept of weight, we expand the previous equation:

[tex]\vec F = \vec N -m\cdot \vec g[/tex] (Eq. 3b)

Where [tex]\vec g[/tex] is the gravitational acceleration, measured in meters per square second.

And then we clear the force of the ground on the man:

[tex]\vec N = \vec F +m\cdot \vec g[/tex] (Eq. 4)

If we get that [tex]\vec F = 1023.673\,\hat{j}\,\,\,\left[N\right][/tex],  [tex]m = 60\,kg[/tex] and [tex]\vec g = 9.807\,\hat{j}\,\,\,\left[\frac{m}{s^{2}} \right][/tex], the average force is:

[tex]\vec N = 1023.673\,\hat{j}\,\,\,[N]+(60\,kg)\cdot (9.807\,\hat{j})\,\,\,\left[\frac{m}{s^{2}} \right][/tex]

[tex]\vec N = 1612.093\,\hat{j}\,\,\,\left[N\right][/tex]

The force of the ground on the man is 1612.093 newtons upwards.

Answer:

no but yes at the same time

Explanation:

they are going a different direction but they are the same speed.

Answer:

  even if it all could be used, it wouldn't be enough

Explanation:

The land area of the US is about 5.45% of the world's area, so the amount of released heat over the area of the US is on the order of 2.4 Tw. Current technology for converting geothermal energy to electricity is about 12% efficient, so the available energy might amount to 0.29 Tw if it could all be captured.

Energy consumption in the US in 2019 was on the order of 0.46 Tw. This suggests that even if all of the thermal energy radiated by the Earth from the US could be turned to useful forms of energy, it would meet only about 60% of the US need for energy.

Answer:

, Nervous tissue is composed of two types of cells, neurons and glial cells. Neurons are the primary type of cell that most anyone associates with the nervous system. They are responsible for the computation and communication that the nervous system provides.

Answer:

like

Explanation:

Have a good day!!

Answer: negitive

Explanation:

Answer:

1.236 rad/s

Explanation:

From the question above,

v = ωr................ Equation 1

Where v = tangental speed, ω = angular speed, r = radius = length of the rope.

Make ω the subject of the equation

ω = v/r.............. Equation 2

Given: v = 8.65 m/s, r = 7.00 m

Substitute these values into equation 2

ω = 8.65/7

ω = 1.236 rad/s

Hence the angular speed is 1.236 rad/s

Answer:

The additional trials needed is 48 trials

Explanation:

Given;

initial number of trials, n = 16 trials

the standard deviation, σ = 0.24 s

initial standard error, ε = 0.06 s

The standard error is given by;

[tex]\epsilon = \frac{\sigma}{\sqrt{n} }[/tex]

To reduce the standard error to 0.03 s, let the additional number of trials = x

[tex]0.03= \frac{0.24}{\sqrt{n+x} } \\\\0.03= \frac{0.24}{\sqrt{16+x} }\\\\0.03\sqrt{16+x} = 0.24\\\\\sqrt{16+x} = \frac{0.24}{0.03} \\\\\sqrt{16+x} = 8\\\\16+x = 8^2\\\\16+x = 64\\\\x = 64 -16\\\\x = 48 \ trials[/tex]

Therefore, the additional trials needed is 48 trials.

Answer:

Explanation:

Given

initial velocity u = 0m/s

final velocity v = 18m/s

To get the time it takes the bird to make this trip, we will use the equation of motion

v = u+gt

g is the acceleration due to gravity = 9.81m/s²

t is the time

Substitute into the formula:

[tex]18 = 0+(9.81)t\\18 = 9.81t\\9.81t = 18\\t = \frac{18}{9.81}\\ t = 1.84secs[/tex]

Hence it took the bird 1.84seconds to make this trip