"On a movie set, an alien spacecraft is to be lifted to a height of 32.0 m for use in a scene. The 260.0-kg spacecraft is attached by ropes to a massless pulley on a crane, and four members of the film's construction crew lift the prop at constant speed by delivering 135 W of power each. If 18.0% of the mechanical energy delivered to the pulley is lost to friction, what is the time interval required to lift the spacecraft to the specified height?"

Answer:

OPTION B is correct

Carbon

Explanation:

element can be defined as a pure substance which cannot be broken down by into smaller units through a chemical method, an element has atoms with identical numbers of protons in their atomic nuclei

Each element is composed of its own type of atom. And this gives the reason why chemical elements are all very different from each other. And all substance on Earth has atoms of at least one of this elements.

There about 118 elements and all arranged in a row and colomn of the periodic table .This elements of the periodic table are arranged by their atomic number, which helps with the chemical properties. Example of elements are; Hydrogen, Oxygeñ, carbon.

Therefore, among the option only carbon is an element because it cannot be broken down into smaller unit unlike water which is made up of oxygen and hydrogen. Also salt is a compound containing more elements.

The substance which represents an element given the following option is carbon (option B)

An element is a pure substance that consist of identical atoms.

An element can not be broken down into simple substances by ordinary methods.

The period table consist of a large number of elements. Some of which are:

We must also understand that when two or more elements are chemically combined together it is called a compound and when they are not chemically combined together, it is called a mixture.

Thus, we can conclude that the correct answer to the question is Carbon (option B)

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Answer:

The angle between the transmission axes of the filters is 65°

Explanation:

The complete question is

Unpolarized light is incident upon two ideal polarizing filters that do not have their transmission axes aligned. If 18% of the light passes through this combination, what is the angle between the transmission axes of the two filters.

From Malus law,

[tex]I = I_{0} cos^{2} \beta[/tex]    ....1

where [tex]I[/tex] is the intensity of the polarized light,

[tex]I_{o}[/tex] is the intensity of the incident light

β the angle between the transmission axes of the two filters

Since the intensity is reduced to 18% or 0.18 of its initial value, this means that

[tex]cos^{2} \beta[/tex] = 0.18

substituting into the equation above, we have

[tex]I = 0.18I_{0}[/tex]    ....2

equating the two equations, we have

[tex]I_{0}cos^{2} \beta[/tex] = [tex]0.18I_{0}[/tex]

[tex]cos^{2}\beta[/tex] = [tex]\frac{0.81I_{0} }{I_{0} }[/tex] = 0.18

[tex]cos \beta[/tex] = [tex]\sqrt{0.18}[/tex] = 0.424

[tex]\beta[/tex] = [tex]cos^{-1} 0.424[/tex] = 64.9 ≅ 65°

Answer:

n_cladding = 1.4764

Explanation:

We are told that θ_max = 5 °

Thus;

θ_max + θ_c = 90°

θ_c = 90° - θ_max

θ_c = 90° - 5°

θ_c = 85°

Now, critical angle is given by;

θ_c = sin^(-1) (n_cladding/n_core)

sin θ_c = (n_cladding/n_core)

n_cladding = (n_core) × sin θ_c

Plugging in the relevant values, we have;

n_cladding = 1.482 × sin 85

n_cladding = 1.4764

Answer:

ω(t) = 0.4 + 0.036 t²

Explanation:  

The angular displacement of the disk is given as the function of time:

β(t) = Ct + B t³

where,

C = 0.4 rad/s

B = 0.012 rad/s³

Therefore,

β(t) = 0.4 t + 0.012 t³

Now, for angular velocity ω(t), we must take derivative of angular displacement with respect to t:

ω(t) = dβ/dt = (d/dt)(0.4 t + 0.012 t³)

ω(t) = 0.4 + 0.036 t²

Explanation:

It is given that,

Angle of incidence from air to another medium, i = 26°

The angle of reflection, r = 32°

We need to find the refractive index of the medium. The ratio of sine of angle of incidence to the sine of angle of reflection is called refractive index. It can be given by :

[tex]n=\dfrac{\sin i}{\sin r}\\\\n=\dfrac{\sin (26)}{\sin (32)}\\\\n=0.82[/tex]

So, the index of refraction is 0.82. Hence, the correct option is C.

Answer:

Explanation:

Energy conservation applies to the swinging of pendulum . When the bob is at one extreme , it is at some height from its lowest point . So it has some gravitational potential energy . At that time since it remains at rest its kinetic energy is zero or the least . As it goes down while swinging , its potential energy decreases and kinetic energy increases following conservation of mechanical energy . At the At the lowest point , its potential energy is least  and kinetic energy is maximum .

In this way , there is conservation of mechanical energy .

A) The free-body diagram of the forces acting on the brick is attached.

B) The free-body diagram of the forces acting on the rubber cushion is attached.

C) The action and reaction forces of the entire brick–cushion–planet system has been enumerated below.

A) The brick has a Mass M placed on top of a rubber cushion of mass m.

This means that there will be a normal force acting acting upwards on the brick and also a gravitational force acting downward. These forces are denoted as;

Normal force of rubber cushion acting on brick = [tex]n_{cb}[/tex]

Gravitational force acting on brick = Mg

Find attached the free body diagram.

B) The forces acting on the cushion will be;

Normal force of parking lot pavement on rubber cushion  = [tex]n_{pc}[/tex]

Gravitational force of earth acting on cushion = mg

Force of brick acting on the rubber cushion = [tex]F_{bc}[/tex]

C)  The action pairs of forces are;

i) Force; Normal force of rubber cushion acting on brick  = [tex]n_{cb}[/tex]

Reaction Force; Force of brick acting on the rubber cushion = [tex]F_{bc}[/tex]

ii) Action Force; Gravitational force acting on brick = Mg

Reaction; Gravitational force of brick acting on the earth

iii) Action Force; Normal force of parking lot pavement on rubber cushion = [tex]n_{pc}[/tex]

Reaction; Force of rubber cushion on parking lot pavement

iv) Action Force; Gravitational force of earth acting on rubber cushion = mg

Reaction Force; Gravitational force of rubber cushion on the earth.

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Answer:

A. the amount of steam added to the air s 0.065kgH20/kg dry air

B.the amount of heat transfer to the air in the heating section is 5.1KJ/Kg of dry air

Explanation:

Pls see attached file

Answer: right side B

Explanation:

Answer:

0.5792g

Explanation:

The computation of the mass of the meter stick is shown below:

Let us assume the following items

x1 = 50 cm;

m2 = m3 = 3.62 g;

x2 = x3 = 20.3 cm;

xcm = 22.5 cm

Based on the above assumption, now we need to apply the equation of center mass which is given below:

[tex]Xcm = \frac{m1x1 + m2x2 + m3x3}{m1 + m2 + m3} \\\\ 22.5 = \frac{m1\times 50 + 3.62 \times 20.3 + 3.62 \times 20.3}{m1 + 3.62 + 3.62}\\\\ 22.5m1 + 162.9 = 50m1 + 73.486 + 73.486[/tex]

27.5 m1 = 15.928

So, the m1  = 0.5792g

Answer:

a)    a = 17.1 m / s², b)    F = 3.04 N

Explanation:

This is an exercise of Newton's second law, in this case the selection of the reference system is very important, we have two possibilities

* a reference system with the horizontal x axis, for this selection the normal and the friction force have x and y components

* a reference system with the x axis parallel to the plane, in this case the weight and the applied force have x and y components

We are going to select the second possibility, since it is the most used in inclined plane problems, let's analyze the angle of the applied force (F) it has an angle 10º with respect to the x axis, if we rotate this axis 30º the new angle is

                θ = 10 -30 = -20º

The negative sign indicates that it is in the fourth quadrant. Let's use trigonometry to find the components of the applied force

              sin (-20) = F_{y} / F

              cos (-20) = Fₓ / F

              F_{y} = F sin (-20)

              Fₓ = F cos (-20)

              F_y = 18 sin (-20) = -6.16 N

              Fₓ = 18 cos (-20) = 16.9 N

The decomposition of the weight is the customary

               sin 30 = Wₓ / W

               cos 30 = W_y / W

               Wₓ = W sin 30 = mg sin 30

                W_y = W cos 30 = m g cos 30

                Wₓ = 0.8 9.8 sin 30 = 3.92 N

                 W_y = 0.8 9.8 cos 30 = 6.79 N

Notice that in the case  the angle is measured with respect to the axis y perpendicular to the plane

Now we can write Newton's second law for each axis

X axis

      Fₓ - fr = m a

Y Axis  

      N - [tex]F_{y}[/tex] - Wy = 0

      N =F_{y} + Wy

      N = 6.16 + 6.79

They both go to the negative side of the axis and

      N = 12.95 N

The friction force has the formula

        fr = μ N

we substitute

        Fₓ - μ N = m a

        a = (Fₓ - μ N) / m

we calculate

       a = (16.9 - 0.25 12.95) / 0.8

       a = 17.1 m / s²

b) now the block slides down with constant speed, therefore the acceleration is zero

ask for the value of the applied force, we will suppose that with the same angle, that is, only its modulus was reduced

       Newton's law for the x axis

              Fₓ -fr = 0

              Fₓ = fr

              F cos 20 = μ N

              F = μ N / cos 20

we calculate

              F = 0.25 12.95 / cos 20

              F = 3.04 N

this is the force applied at an angle of 10º to the horizontal

Answer:

F = F₀ 0.2

Explanation:

For this exercise we apply Coulomb's law with the initial data

     F₀ = k q_A q_B / d²

indicate several changes

q_A ’= ½ q_A

q_B ’= 1/10 q_B

d ’= ½ d

let's substitute these new values ​​in the Coulomb equation

          F = k q_A ’q_B’ / d’²

          F = k ½ q_A 1/10 q_B / (1/2 d)²

          F = (k q_A q_B / d2) ½ 1/10 2²

          F = F₀ 0.2

Answer:

D &B

Explanation:

Using Fleming right hand rule that States that if the fore-finger, middle finger and the thumb of left hand are stretched mutually perpendicular to each other, such that fore-finger points in the direction of magnetic field, the middle finger points in the direction of the motion of positive charge, then the thumb points to the direction of the force

Answer:

The average velocity for this trip is 0 km/hr

Explanation:

We know that average velocity = total displacement/total time.

Now, its displacement is d = final position - initial position.

Since the  car starts and ends at its initial position at Hither, if we assume its initial position is 0 km, then its final position is also 0 km.

So, its displacement is d = 0 km - 0 km = 0 km.

Since the total time for the round trip is 2 hours, the average velocity is

total displacement/ total time = 0 km/2 hr = 0 km/hr.

So the average velocity for this trip is 0 km/hr  

Answer:

a) 2.278 x 10^-5 volts

b) 1.139 x 10^-6 Ampere

c) 2.59 x 10^-11 W

Explanation:

The radius of the wire r = 2 mm = 0.002 m

the number of turns N = 200 turns

direction of the magnetic field ∅ = 25°

magnetic field strength B = 0.02 T

varying time = 2 sec

The cross sectional area of the wire = [tex]\pi r^{2}[/tex]

==> A = 3.142 x [tex]0.002^{2}[/tex] = 1.257 x 10^-5 m^2

Field flux Φ = BA cos ∅ = 0.02 x 1.257 x 10^-5 x cos 25°

==> Φ = 2.278 x 10^-7 Wb

The induced EMF is given as

E = NdΦ/dt

where dΦ/dt = (2.278 x 10^-7)/2 = 1.139 x 10^-7

E = 200 x 1.139 x 10^-7 = 2.278 x 10^-5 volts

b) If the two ends are connected to a resistor of 20 Ω, the current through the resistor is given as

[tex]I[/tex] = E/R

where R is the resistor

[tex]I[/tex] = (2.278 x 10^-5)/20 = 1.139 x 10^-6 Ampere

c) power delivered to the resistor is given as

P = [tex]I[/tex]E

P = (1.139 x 10^-6) x (2.278 x 10^-5) = 2.59 x 10^-11 W

Answer:

The  fraction fraction of the final energy is stored in an initially uncharged capacitor after it has been charging for 3.0 time constants is  

      [tex]k = 0.903[/tex]

Explanation:

From the question we are told that

     The time  constant  [tex]\tau = 3[/tex]

The potential across the capacitor can be mathematically represented as

     [tex]V = V_o (1 - e^{- \tau})[/tex]

Where [tex]V_o[/tex] is the voltage of the capacitor when it is fully charged

    So   at  [tex]\tau = 3[/tex]

     [tex]V = V_o (1 - e^{- 3})[/tex]

     [tex]V = 0.950213 V_o[/tex]

   Generally energy stored in a capacitor is mathematically represented as

             [tex]E = \frac{1}{2 } * C * V ^2[/tex]

In this equation the energy stored is directly proportional to the the square of the potential across the capacitor

Now  since capacitance is  constant  at  [tex]\tau = 3[/tex]

        The  energy stored can be evaluated at as

         [tex]V^2 = (0.950213 V_o )^2[/tex]

       [tex]V^2 = 0.903 V_o ^2[/tex]

Hence the fraction of the energy stored in an initially uncharged capacitor is  

      [tex]k = 0.903[/tex]

Answer:

The resistance of the original circuit is [tex]32\,\,\Omega[/tex]

Explanation:

In the original circuit, we have an unknown resistor that we call R, an unknown power supply that we call V, and the current is 15 Amps. in the second circuit with an added 8 Ω resistor in series, which gives an equivalent resistance of R+8 Ω, using the same power supply V, the current is 12 Amps. SO, we can write a system of two equations with two unknowns as follows:

[tex]V=R\,(15)\\V=(R+8)\,(12)\\then\\15\,R=12\,R+92\\3\,R=96\\R=\frac{96}{3} \,\Omega\\R=32\,\,\Omega[/tex]

Answer:

0.098 N

Explanation:

From the question,

Spring scale reading = W-U............... Equation 1

Where W = weight of the cube, U = upthrust.

W = mg

Where m =  mass of the cube, g = acceleration due to gravity.

Given: m = 11 g = 0.011 kg, g = 9.8 m/s².

W = 0.011(9.8)

W = 0.1078 N.

From Archimedes principle,

Upthrust = weight of water displaced.

U = (Density of water×volume of metal cube)×acceleration due to gravity.

U = (D×V)g

Given: D = 1000 kg/m², V = 1 cm³ = (1/1000000) = 1×10⁻⁶ m³, g - 9.8 m/s²

U = 1000(9.8)(10⁻⁶)

U = 0.0098 N.

Substitute the value of W and U into equation 1

Reading of the spring scale = 0.1078-0.0098

Reading of the spring scale = 0.098 N

Answer:

Explanation:

correct options

a ) Their electrical potential energy keeps decreasing

Actually as they move apart , their electrical potential energy decreases due to increase of distance between them and kinetic energy increases

so a ) option is correct

b ) Their acceleration keeps decreasing

As they move apart , their mutual force of repulsion decreases due to increase of distance between them so the acceleration decreases .

c ) c. Their kinetic energy keeps increasing

Their kinetic energy increases because their electrical potential energy decreases . Conservation of energy law will apply .

The moving apart should be true statements:

a. The electrical potential energy should be reduced.

b. The acceleration should be reduced.

c. The kinetic energy should be increased.

At the time when the moving part, there is the reduction of the electric potential energy because there is a rise in the distance due to which the increment of the kinetic energy.  The reduction of the mutual force of repulsion because of increment in the distance due to this the acceleration should be reduced. There is the increase in the kinetic energy due to the reduction of the electrical potential energy. here the law of conversation of energy should be applied.

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Answer:

μ = 0.03

Explanation:

In order for the trunk not to slide the frictional force between the turntable and the trunk must be equal to the unbalanced force applied on the trunk by the motion of the turntable. Therefore,

Unbalanced Force = Frictional Force

but,

Unbalanced Force = ma (Newton's second law of motion)

Frictional Force = μN = μW = μmg

Therefore,

ma = μmg

a = μg

μ = a/g

where,

μ = coefficient of static friction between the trunk and the turntable = ?

a = tangential acceleration of trunk = 0.3 m/s²

g = 9.8 m/s²

Therefore,

μ = (0.3 m/s²)/(9.8 m/s²)

μ = 0.03

Answer:

Explanation:

Here image distance is fixed .

In the first case if v be image distance

1 / v - 1 / -25 = 1 / .05

1 / v = 1 / .05 - 1 / 25

= 20 - .04 = 19.96

v = .0501 m = 5.01 cm

In the second case

u = 4 ,

1 / v - 1 / - 4 = 1 / .05

1 / v = 20 - 1 / 4 = 19.75

v = .0506 = 5.06 cm

So lens must be moved forward by 5.06 - 5.01 =  .05 cm ( away from film )

Answer:

83.055  m

Explanation:

According to the given scenario, the calculation of skid distance is shown below:-

[tex]S = \frac{1}{2} \times (u + v) \times t[/tex]

Where  

u = 11.3

v = 0

t = 14.7

Now placing these values to the above formula,

So,

[tex]S = \frac{1}{2} \times (11.3 + 0) \times 14.7[/tex]

= 83.055  m

Therefore for computing the skid distance we simply applied the above formula i.e by considering the all items given in the question

Answer:

The speed of the light signal as viewed from the observer is c.

Explanation:

Recall the basic postulate of the theory of relativity that the speed of light is the same in ALL inertial frames. Based on this, the speed of light is independent of the motion of the observer.

Answer:

Sleep, behavior patterns, mental state, and job

Explanation:

Answer:

If I exercise right after school, I might be low on energy. I suppose that I could eat a snack and drink something before my workout. If I exercise before school, I might be tired. But, as long as I keep getting eight to nine hours of sleep, I think that my body will adjust to the new schedule after a while. The trick will be getting to bed on time and eating a little breakfast before I work out. I’m kind of worried that the gym won’t be open early in the morning. On the weekends, my friends might keep me from exercising. I suppose I can try to get them to do it with me. We can pick things that we all like to do. I know they like to play tennis sometimes.

Explanation:

Answer:

Zack should direct his throw outward and toward the back of the car.

Explanation:

As the car is moving forward, the book will be thrown with a forward component. Therefore, throwing this book backwards at a constant speed would cancel the motion of the car, allowing the book to have a greater chance of ending on the driveway. I say a greater chance as Zack may not have the exact timings as to land the book in his driveway. That too he may not have thrown the book with the right momentum.

The solution is throw 3.

I say a greater chance as Zack may not have the exact timings as to land the book in his driveway. That too he may not have thrown the book with the right momentum as the skydivers.

The statement that best applies Newton’s laws of motion to explain the skydiver’s motion is that an upward force balances the downward force of gravity on the skydiver. Newton's 3rd law often applies to skydiving.

When gravity is not acting upon the skydivers they would continue moving in the direction the vehicle they jumped from was moving. If no air resistance takes place, then the skydivers would still accelerating at 9.8 m/s until they hit the ground.

The skydiver after leaving the aircraft will accelerates downwards due to the force of gravity usually as there is no air resistance acting in the upwards direction, and there is a resultant force acting downwards, the skydiver will accelerates towards the ground.

Therefore, I say a greater chance as Zack may not have the exact timings as to land the book in his driveway. That too he may not have thrown the book with the right momentum as the skydivers.

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Answer:

The magnitude of the magnetic field is 8.333 x 10⁻⁷ T

Explanation:

Given;

charge on the lightening bolt, C = 15.0 C

time the charge passes by, t = 1.5 x 10⁻³ s

Current, I is calculated as;

I = q / t

I = 15 / 1.5 x 10⁻³

I = 10,000 A

Magnetic field at a distance from the bolt is calculated as;

[tex]B = \frac{\mu_o I}{2\pi r}[/tex]

where;

μ₀ is permeability of free space = 4π x 10⁻⁷

I is the current in the bolt

r is the distance of the magnetic field from the bolt

[tex]B = \frac{\mu_o I}{2\pi r} \\\\B = \frac{4\pi *10^{-7} 10000}{2\pi *24} \\\\B = 8.333 *10^{-5} \ T[/tex]

Therefore, the magnitude of the magnetic field is 8.333 x 10⁻⁷ T

Answer:

The  critical angle is  [tex]\theta_c = \ 63.68^o[/tex]

Explanation:

From the question we are told that

   The refractive index of the core is  [tex]n_c = 1.35[/tex]

   The refractive index of the cladding  is [tex]n_s = 1.21[/tex]

Generally according to Snell's law

      [tex]\frac{sin i }{sin r } = \frac{n_s}{n_c }[/tex]

Here for total internal reflection the refractive angle is  [tex]r = 90^o[/tex] and  the critical angle is equal to the critical angle so  [tex]i = \theta_c[/tex]

      [tex]\frac{sin \theta_c }{sin (90) } = \frac{n_s}{n_c }[/tex]

substituting values

       [tex]\frac{sin \theta_c }{sin (90) } = \frac{1.21}{1.35 }[/tex]

       [tex]\theta_c = sin^{-1} [\frac{1.21}{1.35} ][/tex]

      [tex]\theta_c = \ 63.68^o[/tex]

Answer:

A)   V = -136.36 V , B)  V = 4.85 10³ V , C)  V = 1.62 10⁴ V

Explanation:

To calculate the potential at an external point of the spheres we use Gauss's law that the charge can be considered at the center of the sphere, therefore the potential for an external point is

          V = k ∑ [tex]q_{i} / r_{i}[/tex]

where [tex]q_{i}[/tex] and [tex]r_{i}[/tex] are the loads and the point distances.

A) We apply this equation to our case

          V = k (q₁ / r₁ + q₂ / r₂)

They ask us for the potential at the midpoint of separation

         r = 3.30 / 2 = 1.65 m

this distance is much greater than the radius of the spheres

let's calculate

         V = 9 10⁹ (1.1 10⁻⁸ / 1.65  + (-3.6 10⁻⁸) / 1.65)

         V = 9 10¹ / 1.65 (1.10 - 3.60)

         V = -136.36 V

B) The potential at the surface sphere A

r₂ is the distance of sphere B above the surface of sphere A

              r₂ = 3.30 -0.02 = 3.28 m

              r₁ = 0.02 m

we calculate

             V = 9 10⁹ (1.1 10⁻⁸ / 0.02  - 3.6 10⁻⁸ / 3.28)

             V = 9 10¹ (55 - 1,098)

             V = 4.85 10³ V

C) The potential on the surface of sphere B

      r₂ = 0.02 m

      r₁ = 3.3 -0.02 = 3.28 m

      V = 9 10⁹ (1.10 10⁻⁸ / 3.28  - 3.6 10⁻⁸ / 0.02)

       V = 9 10¹ (0.335 - 180)

       V = 1.62 10⁴ V

Answer:

The  percentage of the kinetic energy that is left in the system after collision to that before is 0.174 %

Explanation:

Given;

mass of bullet, m₁ = 4g = 0.004kg

initial velocity of bullet, u₁ = 589 m/s

mass of block of wood, m₂ = 2.3 kg

initial velocity of the block of wood, u₂ = 0

let the final velocity of the system after collision = v

Apply the principle of conservation of linear momentum

m₁u₁ + m₂u₂ = v(m₁+m₂)

0.004(589) + 2.3(0) = v(0.004 + 2.3)

2.356 = 2.304v

v = 2.356 / 2.304

v = 1.0226 m/s

Initial kinetic energy of the system

K.E₁ = ¹/₂m₁u₁² + ¹/₂m₂u₂²

K.E₁ = ¹/₂(0.004)(589)² = 693.842 J

Final kinetic energy of the system

K.E₂ = ¹/₂v²(m₁ + m₂)

K.E₂ = ¹/₂ x 1.0226² x (0.004 + 2.3)

K.E₂ = 1.209 J

The kinetic energy left in the system = final kinetic energy of the system

The percentage of the kinetic energy that is left in the system after collision to that before = (K.E₂ / K.E₁) x 100%

                       = (1.209 / 693.842) x 100%

                        = 0.174 %

Therefore, the  percentage of the kinetic energy that is left in the system after collision to that before is 0.174 %

Answer:

The maximum displacement of the mass m₂ [tex]= \frac{2(m_1-m_2)g}{k}[/tex]

Explanation:

Kinetic Energy (K) = 1/2mv²

Potential Energy (P) = mgh

Law of Conservation of energy states that total energy of the system remains constant.

i.e; Total energy before collision = Total energy after collision

This implies that: the gravitational potential energy lost by m₁ must be equal to sum of gravitational energy gained by m₂ and the elastic potential energy stored in the spring.

[tex]m_1gd = m_2gd+\frac{1}{2}kd^2\\\\m_1g = m_2g+\frac{1}{2}kd\\\\d = \frac{2(m_1-m_2)g}{k}[/tex]

d = maximum displacement of the mass m₂

Answer:

The 1/2 inch barrel will burst at the same height of 20 ft

Explanation:

The pressure on a column of fluid increases with depth, and decreases with height. This means that if you increase the height of the fluid in the column, the pressure at the bottom will increase.

From the equation of fluid pressure,

P = ρgh

where

P is the pressure at the bottom of the fluid due to its height

ρ is the density of the fluid in question

h is the height to which the water stand.

You notice how apart from the height 'h' in the equation, all the other parts of the right hand side of the equation cannot be varied; they are a fixed property of the fluid and gravity. And there is no consideration for the horizontal diameter of the water's cross section area.

We can also think of the pressure at the bottom of the fluid to be as a result of an incremental weight of an infinitesimally small vertical section of the water down.

That been said, we can then say that if the barrel with the 1 ft diameter dimension bursts when filled with water up to 20 ft, then, the barrel with the reduced diameter will still burst at the same height as the former pipe.

NB: The only way to stop the pipe from bursting is to increase the thickness of the barrel wall to counteract the pressure forces due to the height.