Q3) A person has to cover a distance of 6km in 45 minutes. If he covers one-half of the distance in two-thirds of the total time; to cover the remaining time, his speed (in km/hr) must be:

A) 6
B) 8
C) 12
D) 15

Explain how you got the answer

If a student rings a brass bell with a frequency of 100 Hz. The sound wave travels through brass, air, and glass, then the wavelength of the wave in brass would be 47 meters, therefore the correct answer is option D.

It is a type of mechanical wave composed of the disturbance caused by the movements of the energy. A sound wave travels through compression and rarefaction in an elastic medium such as air.

As given in the problem if a student rings a brass bell with a frequency of 100 Hz. The sound wave travels through brass, air, and glass, then we have to find out what is the wavelength of the wave,

The wave velocity = Frequency of the wave ×wavelength

4700 = 100 × wavelength

Wavelength = 4700 / 100

                    =47 meters

Thus, the wavelength of the wave would be 47 meters .

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Answer:

Explanation:

Decrease to one half of its original value

Answer:

1.

Astronomers define star brightness in terms of apparent magnitude — how bright the star appears from Earth — and absolute magnitude — how bright the star appears at a standard distance of 32.6 light-years.

2.

Sirius, also known as the Dog Star or Sirius A, is the brightest star in Earth's night sky. The name means "glowing" in Greek — a fitting description, as only a few planets, the full moon and the International Space Station outshine this star.

Answer:

Sirius is the brightest star in the night sky

Explanation:

The name means 'glowing' in greek

Answer:

Explanation:

Mass = 50kg +7kg +4kg =61 kg

Velocity = 3m/s

Momentum = mass × velocity

[tex]p =61\times 3\\\\p =183MLT^-^1[/tex]

Answer:

Mass= 61 kg. Success to The homework.

Answer:

B

Explanation:

Technological advancements in astronomy have led to the development of thousands of products such as

new materials, medical devices, and communications satellites.

For example, the production of instruments like telescopes, microscopes, and other measuring devices now enables us to identify things that we couldn't examine with the naked eye.

Similarly, the development of communication satellites has led to the emergence and improvements in the mobile network industry.

Answer:

The length at 0 °C is 300.05 cm

Coefficient of linear expansion of iron is 1.02×10¯⁵ C¯¹

Explanation:

From the question given above, the following data were obtained:

Length (L₁) at 100 °C = 300.36 cm

Temperature 1 (θ₁) = 100 °C

Length (L₂) at 159 °C = 300.54 cm

Temperature 2 (θ₂) = 159 °C

Length (L₀) at 0 °C =?

Coefficient of linear expansion (α) =?

L₁ = L₀ (1 + θ₁α)

300.36 = L₀ (1 + 100α) ....(1)

L₂ = L₀ (1 + θ₂α)

300.54 = L₀ (1 + 159α) ..... (2)

Divide equation (2) by (1)

300.54 / 300.36 = L₀ (1 + 159α) / L₀ (1 + 100α)

1.0006 = (1 + 159α) / (1 + 100α)

Cross multiply

1.0006 (1 + 100α) = (1 + 159α)

1.0006 + 100.06α = 1 + 159α

Collect like terms

1.0006 – 1 = 159α – 100.06α

0.0006 = 58.94α

Divide both side by 58.94

α = 0.0006 / 58.94

α = 1.02×10¯⁵ C¯¹

Substitute the value of α into anything of the equation to obtain L₀. Here we shall use equation (2).

300.54 = L₀ (1 + 159α)

α = 1.02×10¯⁵ C¯¹

300.54 = L₀ (1 + 159 ×1.02×10¯⁵)

300.54 = L₀ (1 + 0.0016218)

300.54 = L₀ (1.0016218)

Divide both side by 1.0016

L₀ = 300.54 / 1.0016

L₀ = 300.05 cm

Summary:

The length at 0 °C is 300.05 cm

Coefficient of linear expansion of iron is 1.02×10¯⁵ C¯¹

Answer:

C) plate movement at fault lines.

Explanation:

Earthquakes are vibrations that develop when there is a build-up of stress in the Earth's crust resulting in plate movement at fault lines. Most often, earthquakes occur at subduction zones.

Answer:

they all will die and so will we

Explanation:

Answer:

3 animals will thrive better

Explanation:

If the number of wolves is reduced, 3 animal species usually eaten by the wolves will have a better chance of survival.

Answer:

i cant see it just put the question

Explanation:

Answer:

glucose

Explanation:

Answer:

C

Explanation:

Because I said so

When a sound source approaches us, it sounds like more pushed towards the observer with a decreased wavelength and increasing frequency. As its frequency increases, its energy and intensity increases.

A wave's frequency changes in response to an observer moving in respect to the wave source, which is known as the Doppler effect or Doppler shift. 

The apparent pitch increases as one gets closer to a blowing horn until they reach it, then decreases as they pass it. This is an example of the Doppler effect.

Similar to how a star's light changes as seen from earth by moving toward the red end of the spectrum that is lower frequency or longer wavelength when the Earth and star are moving apart, and toward the violet end of the spectrum when they are drawing nearer. Therefore, option D  is correct.

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Answer:

I believe it is the first one

Answer:

Do i ansa that?

Explanation:

Answer:

Explanation:

Average speed is always: ( total distance traveled ) / ( time elapsed )

The time for the walk is +150+%2B+30+%2B+140+=+320+ s

The distance traveled is +160+%2B+210+=+370+ m

( total distance traveled ) / ( time elapsed ) = +370+%2F+320+=+1.156+ m/s

Answer:

hi have a nice day

Explanation:

i think forms of space

Answer:

Transverse waves

Explanation:

EM waves are made up of photons, which are massless particles. These waves propogate (travel) through space at the speed of light as transverse waves, waves that move back and forth perpendicular to the direction they're travelling in, as opposed to longitudinal waves, which move back and forth along the path of travel.

Answer: Mid-ocean ridges are geologically important because they occur along the kind of plate boundary where new ocean floor is created as the plates spread apart. Thus the mid-ocean ridge is also known as a "spreading center" or a "divergent plate boundary." The plates spread apart at rates of 1 cm to 20 cm per year.

Answer:  The mid-ocean ridge system is the most extensive chain of mountains on earth, but more than 90% of this mountain range lies in the deep ocean. The mid-ocean ridge wraps around the globe for more than 65,000 km like the seam of a baseball. The average depth to the crest (top) of the ridge is 2500 m, but it rises above sea-level in Iceland and is more than 4000 m deep in the Cayman Trough.

Answer:Acceleration

Explanation:Acceleration

increases at time decreases

Answer:

Acceleration

Explanation:

The list of the type of forces that are weakest at the top to strongest at the bottom is  

The type of force that impacts the objects are physical, tension and normal, gravitational, electric, and magnetic force. The force that is strongest is that of the iconic bonds and the weakest is that of the Van der Waals force.

Find out more information bout the types of forces.

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Answer:

C. Van der Waals forces

Hydrogen bonds

Metallic bonds

Ionic bonds

Explanation:

This list orders the types of forces from weakest at the top to strongest at the bottom. Van der Waals forces are relatively weak intermolecular forces, followed by hydrogen bonds which are stronger. Metallic bonds are even stronger, and ionic bonds are the strongest among the listed forces.

Answer:

a. Please find the attached velocity time graph of the car's motion created with Microsoft Excel

b. The total distance traveled by the car is 8,725 meters

c. The average speed of the car is 22.9605263 m/s

Explanation:

The given parameters of the motion are;

The initial speed of the car, v₁ = 15 m/s

The time during which the car runs at the initial speed, t₁ = 30 seconds

The new speed the car then accelerates at 'a₁' to, v₂ = 25 m/s

The duration it takes for the car to accelerate to the new speed = 20 seconds

The time during which the car runs at the initial speed = 300 seconds

The time it takes the car to be brought to rest with a deceleration, 'a₂' from the new speed (20 m/s) = 30 seconds

The final speed of the car at rest, v₃ = 0 m/s

The acceleration, a₁ = (v₂ - v₁)/t₁ = (25 - 15)/20 = 1/2 m/s²

The deceleration , a₂ = (v₃ - v₂)/t₁ = (0 - 25)/30 = -5/6 m/s²

a. Please find attached the drawing of the velocity time graph of the motion created with Microsoft Excel

b. The total distance traveled by the car, 'Δx', is given b the area under the velocity time graph as follows;

Area of trapezoid, A₁ = (320 + 300)/2 × 10 = 3,100

Area of rectangle, A₂ = 15 × 350 = 5,250

Area of triangle, A₃ = 1/2×30×25 = 375

The total area under the velocity time graph = A₁ + A₂ + A₃ = 3,100 + 5,250 + 375 = 8,725

The total area under the velocity time graph = The total distance traveled by the car, Δx = 8,725 meters

c. The average speed of the car is given as follows;

[tex]The \ average \ speed \ of \ the \ car, \overline v =\dfrac{\Delta x}{\Delta t} = \dfrac{The \ total \ distance \ traveled by \ the \ car}{The \ total \ time \ the \ car \ travels}[/tex]

Where;

Δt = The total time during which the car travels

∴ The average speed of the car = 8,725 m/(380 s) = 22.9605263 m/s

Answer:

B

Explanation:

Answer:

Explanation:

Let the resistance placed across the 3.6ohms be x, this means that they are both connected in parallel and then in series to 4.56 ohms;

The equivalent resistance is expressed as;

RT = (1/3.6+1/x) + 4.56

RT = 3.6x/3.6+x + 4.56

Since RT = 6ohms

6 = 3.6x/3.6+x + 4.56

6 - 4.56 = 3.6x/3.6+x

1.44= 3.6x/3.6+x

1.44(3.6+x) = 3.6x

5.184+ 1.44x = 3.6x

5.184 = 3.66x - 1.44x

5.184 = 2.22x

x = 5.184/2.22

x = 2.34  ohms

Hence the resistance that must be placed across 3.6ohms so that total resistance of the circuit shall be 6ohms is 2.34 ohms

Answer:

v = 5.4 m/s

Explanation:

We use conservation of mechanical energy, that is all potential energy in the initial state, and all kinetic energy in the final state:

[tex]m*g*h=\frac{1}{2} m*v^2\\g*1.5=\frac{1}{2} v^2\\v^2=3*g=29.4\\v=\sqrt{29.4} \\v=5.42\,m/s[/tex]

which rounded to one decimal is

v = 5.4 m/s

(in agreement with the third answer on the list)

Answer:

The Rutherford Model shows an atom with electrons orbiting a fixed, positively charged nucleus in set, predictable paths. The Bohr model shows electrons travel in defined circular orbits around the nucleus.

Explanation:

Answer:

it take 15 seconds

Explanation:

it take 15 seconds to increase it time