Which of the following is a sustainable method of resource management?
A. Removing the insulation around windows
O
O
B. Releasing pollutants into the atmosphere
O
C. Using only renewable energy resources
D. Taking longer showers than necessary
O

Answer:

Option A. The speed of sound through water is 4.3 times faster than sound through air.

Explanation:

To answer the question correctly, we shall determine the speed of the wave in both cases. This is illustrated below:

For Air:

Frequency (fₐ) = 195 Hz

Wavelength (λₐ) = 1.76 m

Velocity (vₐ) =?

vₐ = λₐfₐ

vₐ = 1.76 × 195

vₐ = 343.2 m/s

For Water:

Frequency (fᵥᵥ) = 195 Hz

Wavelength (λᵥᵥ) = 7.6 m

Velocity (vᵥᵥ) =?

vᵥᵥ = λᵥᵥfᵥᵥ

vᵥᵥ = 7.6 × 195

vᵥᵥ = 1482 m/s

Finally, we shall compare the speed in water to that of air. This can be obtained as follow:

Velocity in air (vₐ) = 343.2 m/s

Velocity in water (vᵥᵥ) = 1482 m/s

Water : Air

vᵥᵥ : vₐ =>

vᵥᵥ / vₐ = 1482 / 343.2

vᵥᵥ / vₐ = 4.3

Cross multiply

vᵥᵥ = 4.3 × vₐ

Thus, the speed in water is 4.3 times the speed in air.

Option A gives the correct answer to the question.

Answer:

Magdeburg hemispheres are a pair of large copper hemispheres, with mating rims.

Explanation:

They were used to demonstrate the power of atmospheric pressure. When the rims were sealed with grease and the air was pumped out, the sphere contained a vacuum and could not be pulled apart by teams of horses.

Solution :

We know, resistance is given by :

[tex]R = \dfrac{\rho l}{A}[/tex]

[tex]A = \dfrac{\rho l }{R}\\\\A = \dfrac{1.72\times 10^{-8} \times 3.5 }{0.125}\\\\A = 4.816 \times 10^{-7} \ m^2[/tex]

Now, we know mass of wire is given by :

[tex]Mass = Density \times Volume\\\\\M = 8.9 \times 10^3 \times 4.816 \times 10^{-7} \times 3.5 kg\\\\M = 0.01500\ kg\\\\M = 15.00\ gram[/tex]

Hence, this is the required solution.

Given:

The resistance will be:

→ [tex]R = \frac{\rho l}{A}[/tex]

or,

→ [tex]A = \frac{\rho l}{R}[/tex]

By substituting the values, we get

      [tex]= \frac{1.72\times 10^{-8}\times 3.5}{0.125}[/tex]

      [tex]= 4.816\times 10^{-7} \ m^2[/tex]

hence,

The mass will be:

→ [tex]Mass = Density\times Volume[/tex]

             [tex]= 8.9\times 10^3\times 4.816\times 10^{-7}\times 3.5[/tex]

             [tex]= 0.01500 \ kg[/tex]

             [tex]= 15.00 \ g[/tex]

Thus the above answer is right.  

Learn more about mass here:

https://brainly.com/question/17108656

Answer:

Appliance A and B can work together without tripping

Explanation:

We will calculate the amount of current consumed by each appliances.

Appliance A

P = VI

I = P/V  

I = 250/120 = 2.08 A

Appliance B

I = 480 /120 = 4 A

Appliance C

I = 1450/120

I = 12.08 A

Hence, appliance C will trip the circuit as it consumes a lot of electricity.

Explanation:

The range R of a projectile is given by

[tex]R = \frac{v_0^2}{g} \sin 2\theta[/tex]

The maximum range [tex]R_{max}[/tex] occurs when [tex]\sin 2\theta = 1\:\text{or}\:\theta = 45°[/tex]. Let [tex]\alpha[/tex] be the angle above or below 45°. Now let's look at the ranges brought about by these angle differences.

Case 1: Angle above 45°

We can write the range as

[tex]R_+ = \dfrac{v_0^2}{g} \sin 2(45° + \alpha)= \dfrac{v_0^2}{g} \sin (90° + 2\alpha)[/tex]

[tex]\:\:\:\:\:\:\:= \dfrac{v_0^2}{g} (\sin 90° \cos 2\alpha + \cos 90° \sin 2\alpha)[/tex]

[tex]\:\:\:\:\:\:\:= \dfrac{v_0^2}{g} \cos 2\alpha\:\:\:\:\:(1)[/tex]

Case 2: Angle below 45°

We can write the range as

[tex]R_- = \dfrac{v_0^2}{g} \sin 2(45° - \alpha)= \dfrac{v_0^2}{g} \sin (90° - 2\alpha)[/tex]

[tex]\:\:\:\:\:\:\:= \dfrac{v_0^2}{g} (\sin 90° \cos 2\alpha - \cos 90° \sin 2\alpha)[/tex]

[tex]\:\:\:\:\:\:\:= \dfrac{v_0^2}{g} \cos 2\alpha\:\:\:\:\:(2)[/tex]

Note that the equations (1) and (2) are identical. Therefore, the ranges are equal if they differ from 45° by the same amount.

Answer:

the maximum vertical height the person in the cart can reach is 18.42 m

Explanation:

Given;

mass of the person, m₁ = 45 kg

mass of the cart, m₂ = 43 kg

velocity of the system, v = 19 m/s

let the maximum vertical height reached = h

Apply the principle of conservation mechanical energy;

[tex]P.E = K.E\\\\mgh_{max} = \frac{1}{2} mv^2_{max}\\\\gh_{max} = \frac{1}{2} v^2_{max}\\\\h_{max} = \frac{v_{max}^2}{2g} \\\\h_{max} = \frac{19^2}{2\times 9.8} \\\\h_{max} = 18.42 \ m[/tex]

Therefore, the maximum vertical height the person in the cart can reach is 18.42 m

Answer: The speed of gymnast at the bottom of the swing is 6.44 m/s.

Explanation:

Given: Distance = 1.06 m

According to the law of conservation of energy, the speed is calculated as follows.

[tex]mgh = - mgh + \frac{1}{2}mv^{2}\\gh = - gh + \frac{1}{2}v^{2}\\v = \sqrt{4gh}[/tex]

where,

g = acceleration due to gravity = 9.8 [tex]m/s^{2}[/tex]

h = distance

v = speed

Substitute the values into above formula as follows.

[tex]v = \sqrt{4gh}\\= \sqrt{4 \times 9.8 m/s^{2} \times 1.06}\\= 6.44 m/s[/tex]

Thus, we can conclude that speed of gymnast at the bottom of the swing is 6.44 m/s.

Answer:

plz mark brainliest again lol :)

Explanation:

When you drop a ball from a greater height, it has more kinetic energy just before it hits the floor and stores more energy during the bounce—it dents farther as it comes to a stop.

Answer:

When you drop a ball from a greater height, there is more potential energy. When you release the ball, the potential energy turns into kinetic energy. When the ball bounces off the ground, the ball go upward and then it has more potential energy. Then when it goes down it has more kinetic energy. The ball keeps doing this until there is not enough potential energy left.

Explanation:

Answer:

378 KWh

Explanation:

We'll begin by converting 1.2×10³ W to KW. This can be obtained as follow:

10³ W = 1 KW

Therefore,

1.2×10³ W = 1.2×10³ W × 1 KW / 10³ W

1.2×10³ W = 1.2 KW

Next, we shall convert 6.3×10² mins to hours (h). This can be obtained as follow:

60 mins = 1 h

Therefore,

6.3×10² mins = 6.3×10² mins × 1 h / 60 mins

6.3×10² mins = 10.5 h

Finally, we shall determine the electrical energy in KWh used for 1 month (i.e 30 days). This can be obtained as follow:

Power (P) = 1.2 KW

Time (t) for 1 month (30 days) = 10.5 h × 30

= 315 h

Energy (E) =?

E = Pt

E = 1.2 × 315

E = 378 KWh

Thus, the electrical energy used for 1 month (i.e 30 days) is 378 KWh.

Answer:

2.0km/h.

Explanation:

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The scenario when a scientist makes a judgment that a rock sample is volcanic because of the rock's texture and mineral composition is an example of a scientific way of thinking, therefore the correct answer is option B.

Scientific claims are statements made in science based on an experiment.

These Scientific claims are backed by experimental data and their true results obtained from scientific investigation and experimentation.

A good illustration of a scientific mode of thinking is when a scientist determines that a rock sample is volcanic based on its texture and mineral makeup.

Thus, The scenario when a scientist makes a judgment that a rock sample is volcanic because of the rock's texture and mineral composition is an example of a scientific way of thinking, therefore the correct answer is option B.

To learn more about the scientific claims here, refer to the link

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Answer:

E = 66.44 J

Explanation:

From the law of conservation of energy:

Total Mechanical Energy at Start = Total Mechanical Energy at the End

Potential Energy at Start = Kinetic Energy at End + Energy Lost

[tex]mgh = \frac{1}{2} mv^2 + E\\\\E = mgh - \frac{1}{2} mv^2\\\\[/tex]

where,

E = Energy turned into heat = ?

m = mass of block = 2 kg

g = acceleration due to gravity = 9.81 m/s²

h = height = 12 m

v = final speed = 13 m/s

Therefore,

[tex]E = (2\ kg)(9.81\ m/s^2)(12\ m)-\frac{1}{2} (2\ kg)(13\ m/s)^2\\\\E = 235.44\ J - 169\ J\\[/tex]

E = 66.44 J

This question is incomplete, the complete question is;

Model a hydrogen atom as a three-dimensional potential well with U₀ = 0 in the region 0 < x < L, 0 < y < L and 0 < z < L, and infinite otherwise, with L = 1.0 × 10⁻¹⁰ m.

Which of the following is NOT one of the lowest three energy levels of an electron in this model?

a. 283 eV

b. 339 eV

c. 113   eV  

d. 226 eV        

Answer:

the lowest three energy are; 113 eV, 225 eV, and 339 eV.

Hence Option a) 283 eV is not among the three lowest energy

Explanation:

Given the data in the question;

Three dimension cube or particle in a cubic box

the energy value is given by;

[tex]E_{nx,ny,nz[/tex] = [tex]( n_x^2 + n_y^2 + n_z^2 )[/tex] × π²h"² / 2ml²

where h" = h/2π and h is Planck's constant ( 6.626 × 10⁻³⁴ m² kg / s )

m is mass of electron ( 9.1 × 10⁻³¹ kg )

l is length of side of box ( 1.0 × 10⁻¹⁰ m )

for ground level ( [tex]n_x = n_y = n_z = 1[/tex] )

so

[tex]( n_x^2 + n_y^2 + n_z^2 )[/tex] ×  π²h"² / 2ml²

since h" = h/2π

[tex]( n_x^2 + n_y^2 + n_z^2 )[/tex] × π²h² / (2π)²2ml²

so we substitute

[tex]E_{111[/tex] = ( 1² + 1² + 1² ) × [ π²( 6.626 × 10⁻³⁴ )² ] / [ (2π)² × 2 × 9.1 × 10⁻³¹ kg × ( 1.0 × 10⁻¹⁰)² ]

[tex]E_{111[/tex] = 3 × [ (4.333188779 × 10⁻⁶⁶) / ( 7.185072 × 10⁻⁴⁹ ) ]    

[tex]E_{111[/tex] = 3 × [ 6.03082165 × 10⁻¹⁸ ]

Now, we know that electric charge = 1.602 x 10⁻¹⁹

so

[tex]E_{111[/tex] = 3 × [ (6.03082165 × 10⁻¹⁸) / (1.602 x 10⁻¹⁹) ]

[tex]E_{111[/tex] = 3 × [ 37.645578 ]

[tex]E_{111[/tex] = 112.9 ≈ 113 eV

[tex]E_{211[/tex] = [tex]( n_x^2 + n_y^2 + n_z^2 )[/tex]  × π²h² / (2π)²2ml²

we substitute

[tex]E_{211[/tex] = ( 1² + 1² + 2² ) × [ 37.645578 ]

[tex]E_{211[/tex] = 6 × [ 37.645578 ]

[tex]E_{211[/tex] = 225.87 ≈ 226 eV

[tex]E_{221[/tex] = [tex]( n_x^2 + n_y^2 + n_z^2 )[/tex]  × π²h² / (2π)²2ml²

we substitute

[tex]E_{221[/tex] = ( 2² + 2² + 1² ) × [ 37.645578 ]

[tex]E_{211[/tex] = 9 × [ 37.645578 ]

[tex]E_{211[/tex] = 338.8 ≈ 339 eV

Therefore, the lowest three energy are; 113 eV, 225 eV, and 339 eV.

Hence Option a) 283 eV is not among the three lowest energy

Answer:im just guessing d but i think its d though

Explanation:

it pretty obvious

Answer: Pressure increases as the depth increases.

Answer:

depths cause it help it with a lot and that it the answer

Answer:

v_f = 10.38 m / s

Explanation:

For this exercise we can use the relationship between work and kinetic energy

          W = ΔK

note that the two quantities are scalars

Work is defined by the relation

          W = F. Δx

the bold are vectors.  The displacement is

          Δx = r_f -r₀

          Δx = (11.6 i - 2j) - (4.4 i + 5j)

          Δx = (7.2 i - 7 j) m

          W = (4 i - 9j). (7.2 i - 7 j)

remember that the dot product

           i.i = j.j = 1

           i.j = 0

           W = 4  7.2 + 9  7

           W = 91.8 J

the initial kinetic energy is

           Ko = ½ m vo²

           Ko = ½ 2.0 4.0²

           Ko = 16 J

we substitute in the initial equation

          W = K_f - K₀

          K_f = W + K₀

          ½ m v_f² = W + K₀

          v_f² = 2 / m (W + K₀)

          v_f² = 2/2 (91.8 + 16)

           v_f = √107.8

          v_f = 10.38 m / s

Answer:

According to the parallelogram law of vector addition if two vectors act along two adjacent sides of a parallelogram(having magnitude equal to the length of the sides) both pointing away from the common vertex, then the resultant is represented by the diagonal of the parallelogram passing through the same common vertex

Explanation:

DL: Activity 2.3 Resistance

Complete the questions based on the Resistance presentation.

a. All resistors ___________ or _____________ the flow of electrons.

b. As resistance __________________ current _______________________

a) limits or opposes

b) increases, decreases

Resistors are electrical devices used to resist, limit, oppose or hinder the flow of electrons in a circuit. This resistance causes a reduction in current and an increase in voltage in the circuit. In order words, as resistance increases, the current decreases and voltage increases.

This was further stated by Ohm's law that states that as long as the resistance in a wire/conductor remains constant, the voltage across it is directly proportional to the current flowing through a conductor. i.e

V = IR

Where;

R = constant called resistance

I = current flowing through the wire

V = voltage across the wire

Answer:

(a) 490 N

(b) 490 N

(c) 540 N

Explanation:

mass, m = 50 kg

acceleration, a = 1 m/s2

(a) The weight is given by

W = m g = 50 x 9.8 = 490 N

(b) The normal force is

N = m g = 490 N

(c) Let the force required is F.

Use Newton's second law

F - m g = m a

F = m(g + a)

F = 50(9.8 + 1)

F = 540 N

Answer:

[tex]F=32.24N[/tex]

Explanation:

From the question we are told that:

Height [tex]h= 2.75 m[/tex]

Length[tex]l = 5.25 m[/tex]

Mass [tex]m=45kg[/tex]

Final speed [tex]v_f=6.81[/tex]

Generally the equation for Potential Energy P.E is mathematically given by

[tex]P.E=mgh[/tex]

Therefore

Initial potential energy

[tex]P.E_1=45*9.8*2.75 \\\\P.E_1= 1212.75 J[/tex]

Generally the equation for Kinetic Energy K.E is mathematically given by

[tex]K.E=0.5mv^2[/tex]

Therefore

Final kinetic energy

[tex]K.E_2= 1/2*45*6.81*6.81 \\\\K.E_2= 1043.46J[/tex]

Generally the equation for Work_done is mathematically given by

[tex]W=P.E_1-K.E_2\\\\W=169.3[/tex]

Therefore

[tex]F=\frac{W}{d}\\\\F=\frac{169.3}{5.25}[/tex]

[tex]F=32.24N[/tex]

This question is incomplete, the complete question is;

Consider the cylindrical weir of diameter 3m and length 6m. If the fluid on the left has a specific gravity of 1.6 and on the right has a specific gravity of 0.8, Find the magnitude and direction of the resultant force.

Answer:

- the magnitude of the resultant force is 557.32 kN

- the direction of resultant force is  48.29°

Explanation:

Given the data in the question and the diagram below,

First we work on the force on the left hand side.

Left Horizontal

[tex]F_{LH[/tex] = βgAr

here, h = 3/2 = 1.5 m, β = 1.6, g = 9.81 m/s², A = 3 m × 6 m = 18 m²

we substitute

[tex]F_{LH[/tex] = βgAh = ( 1.6 × 1000 ) × 9.81 × 18 × 1.5 = 423792 N

Left Vertical

[tex]F_{LV[/tex] = ( βgπh² / 2 ) × W

we substitute

[tex]F_{LV[/tex] = [ ( ( 1.6 × 1000 ) × 9.81  × π(1.5)² ) / 2 ] × 6 = 332845.458 N

Now we go to the right hand side

Right Horizontal

[tex]F_{RH[/tex] = βgAh

here, h' = 1.5/2 = 0.75 m, β = 0.8, g = 9.81 m/s², A = 1.5 m × 6 m = 9 m²

we substitute

[tex]F_{RH[/tex] = ( 0.8 × 1000 ) × 9.81 × 9 × 0.75 ) = 52974 N

Right Vertical

[tex]F_{RV[/tex] = ( βgπh² / 4 ) × W

we substitute

[tex]F_{RV[/tex] = [ ( ( 0.8 × 1000 ) × 9.81  × π(1.5)² ) / 4 ] × 6 =  83211.36 N

Hence

Fx = [tex]F_{LH[/tex] - [tex]F_{RH[/tex] = 52974 N - 423792 N =  370818 N

Fy = [tex]F_{LV[/tex] + [tex]F_{RV[/tex] = 332845.458 N + 83211.36 N = 416056.818 N

R = √( Fx² + Fy² ) = √[ (370818 N)² + (416056.818 N)² ] = 557323.3 N

R = 557.32 kN

Therefore, the magnitude of the resultant force is 557.32 kN

Direction of resultant force;

tanθ = Fy / Fx

we substitute

tanθ = 416056.818 N / 370818 N

tanθ = 1.121997

θ = tan⁻¹( 1.121997 )

θ = 48.29°

Therefore, the direction of resultant force is  48.29°

Answer:

Here are a few recommendations based on IOM's Migration Governance Framework: Countries should promote stability, education and employment opportunities and reduce the drivers of forced migration, including by promoting resilience, thereby enabling individuals to make the choice between staying or migrating.

Explanation:

thank me later

Answer:

Energy conversion in flashlight.

Explanation:

When the switch of a flashlight is on, then the batteries inside them will be connected in a circuit and chemical energy from the batteries will be converted into electrical energy and then the electrical energy will be converted into light energy.

Light energy is also called electromagnetic energy.

Hence, among the given options the correct one is the first option that is:

1. Electrical energy into electromagnetic energy is the answer.

Answer:

[tex]m=1.47\times 10^{-24}\ Kg[/tex]

Explanation:

Given that,

Charge, [tex]q=1.6\times 10^{-19}\ C[/tex]

Revolution = 7 rev

magnetic field, B = 45 mT

Time, t = 1.29 ms

We need to find the mass of the ion. Let m be the mass. The formula for the mass in terms of time period is given by :

[tex]m=\dfrac{qBT}{2\pi}\\\\m=\dfrac{1.6\times 10^{-19}\times 45\times 10^{-3}\times 1.29\times 10^{-3}}{2\pi}\\\\m=1.47\times 10^{-24}\ Kg[/tex]

So, the mass of the ion is equal to [tex]1.47\times 10^{-24}\ Kg[/tex].

Answer:

B

Explanation:

Cause its true

Answer:

7.48 cm

Explanation:

The diagrammatic representation of information is shown in the image below:

From the image, Δ X₁X₂ and Δ Y₁Y₂ are equivalent triangles.

where;

X₁X₂ = width of the aperture

Using equivalent triangles, It implies that:

[tex]\implies \dfrac{X_1X_2}{Y_1Y_2} = \dfrac{1.70}{1.70+0.800} \\ \\ \implies X_1X_2=\dfrac{1.70}{1.70+0.800}\times 11.0[/tex]

[tex]X_1X_2= \dfrac{1.70}{2.50}\times 11.0 cm[/tex]

X₁X₂ = 7.48 cm