ECONOMIC Q‼️
Which of these is a common concern of an economist ?

A-The distributions of populations and earths resources
B-How people have organized the rules and laws of their societies
C-The cultural habits and social customs of societies
D-How well resources are used by a society

Answer:

Radio waves

Explanation:

The radio operates by the principles of radio wave.

Electromagnetic wave is a type of wave which does not require material medium for its propagation. A radio wave is an example of electromagnetic wave.

The radio operates in the principle of electromagnetic wave because it does not require material medium for its propagation and it has one of the longest frequency of electromagnetic spectrum.

Thus, we can conclude that the radio operates by the principles of radio wave.

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Answer:

1. A

2. A; distance is scalar, displacement is vector

3. C ; position is on the y-axis

The velocity of the person as seen by someone not moving (watching the train going by) will be 55 m/s South. I can therefore conclude that none of the option given is correct.

Given that a train is moving south at 50 m/s and a person is running SOUTH on the train at 5 m/s.

That means the person is running relatively to the velocity of the train. Since the train and the person are moving in the same direction, the relative velocity seen by an observer watching the train going will be the addition of both the train and the person in the direction of the train.

That is,

Relative velocity = 50 + 5

Relative velocity = 55 m/s South.

Therefore, the velocity of the person as seen by someone not moving (watching the train going by) will be 55 m/s South.

I can therefore conclude that none of the option given is correct.

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Answer:

D

Explanation:

Answer:

The orbital speeds of stars far from the galactic center are surprisingly high, suggesting that these stars are feeling gravitational effects from unseen matter in the halo.

Answer:

The light waves are refracted as they enter and leave the prism. The shorter the wavelength of the light, the more it is refracted. As a result, red light is refracted the least and violet light is refracted the most - causing the coloured light to spread out to form a spectrum.

Explanation:

hope this helps

Answer: Neither, its actually violet aka purple. This is because it has the shortest wavelength. This is also why red light is refracted the least because it has the longest wavelength.

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The tension in the horizontal portion of the rope provided the blocks are not moving and the rope has negligible mass is 40 N

The tension in the rope is a pulling force that acts on the rope when the mass of 4kg is placed on each side of the two frictionless pulley.

According to Newton's second Law;

Force = (Tension) = mass × acceleration due to gravity

∴

We can say:

Tension = 4kg × 9.81 m/s²

Tension = 39.24 N

Tension = 40 N (to the nearest whole number)

Therefore, we can conclude that the tension in the horizontal portion of the rope is 40 N

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Answer:

finish the question pls

Explanation:

Answer:  When we use an analogy that represents the expanding universe with the surface of an expanding balloon, what does the inside of the balloon represent? The inside of the balloon does not represent any part of our universe.

Answer:

Answer should be (B)

Explanation:

If the forces on an object are balanced (or if there are no forces acting on it), this is what happens: a stationary object stays still. a moving object continues to move at the same speed and in the same direction.

ALSO: forces acting upon an object are balanced, then the object will maintain its state of motion. To maintain the state of motion is to keep the current speed and direction. But if the forces are not balanced, the object will change its state of motion.

Answer:

Work done,W= 250J

Displacement , s = 60

We know that, Work done = Force x displacement

i.e , W = Fxs

250 J = F x 60m

F = 250/60

=4.16 N

Hence , 4.16 N of Force is applied on the body.

Please find attached photograph for your answer.

Hope it helps.

Do comment if you have any query.

Answer:

Absorption

Explanation:

the disappearance of an EM wave into the medium. scattering – the spreading out of light rays in all directions because particles reflect and absorb the light.

Answer:

the condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death.

Explanation:

hope this helps

Answer:

I = 138.75N*s

Explanation:

I = F*t

I = Impulse or momentum

t = Time or duration

F = Force

I = 18,500N*0.0075s

I = 138.75N*s

Answer:

Explanation:

The force acting on an object given it's mass and acceleration can be found by using the formula

force = mass × acceleration

From the question

mass = 80 kg

acceleration = 2 m/s²

We have

force = 80 × 2 = 160

We have the final answer as

Hope this helps you

Answer:

C) 5ML^2

Explanation:

2 Spheres of mass M

Bug's mass 3M

Rod length 2L, radius L

Find Rotational Inertia I

I=Σmr^2

I=(3M+M+M)L^2

I=5ML^2

The rotational inertia of the bug-rod-spheres system about the horizontal axis through the center of the rod is 5ML².

The rotational inertia of the system is determined by summing all the masses together and multiply with the radius.

I(t) = Σmr²

Where;

I(t) = Inertia of the 2 spheres + inertia of the bug

I(t) = (M + M)L²  + (3M)L²

I(t) = 2ML² + 3ML²

I(t) = 5ML²

Thus, the rotational inertia of the bug-rod-spheres system about the horizontal axis through the center of the rod is 5ML².

Complete question is below:

There are 2 Spheres of mass M and Bug's mass 3M. The Rod length is 2L, radius L.

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Answer:

50km/hour

Explanation:

the average speed and the speed are the same

Answer:

2.45 g/mL

Explanation:

(assuming that the original volume was 20 mL and not L)

Since you know the amount of water in the cylinder before and after you placed the rock in, you can subtract them to get the volume of the rock itself. [tex]30.2-20=10.2[/tex] mL.

To get the rock's density, use the equation [tex]d=\frac{m}{v}[/tex], where m is mass and v is volume.

[tex]d=\frac{25 g}{10.2mL}\\\\d=2.45 g/mL[/tex]

Answer:

Explanation:

Use simplified formula:

Answer:

"rings" - viewed from a distance, Saturn appears to be surrounded by rings

Answer:

you

Explanation:

you will be used is this frl?

Answer:

Work = Force × Distance

Therefore Force = Work/Distance

= 45 joules/3 metres

= 15 newton

Explanation:

Answer:

15

Explanation:

15

Answer:

a smooth

b less smooth

c faster

d faster than fast c

e to fast for fast

Explanation:

Hi there!

Since the ball is directed 60° above the horizontal, we must use its HORIZONTAL component to find its displacement.

We can take the cosine to do so:

vcosθ = 28.3cos(60) = 14.15 m/s

Since the ball is in the air for 5 sec, we can use the following equation:

displacement = velocity · time (d = vt)

Plug in the values:

d = 14.15 · 5 = 70.75 m

Answer:

The answer is #3: The kinetic energy of water is converted by a generator into electric energy.

Explanation:

Hydropower plants capture the energy of falling water to generate electricity. A turbine converts the kinetic energy of falling water into mechanical energy. Then a generator converts the mechanical energy from the turbine into electrical energy.