Dark matter is inferred to exist because it explains the abundance of helium in the universe today. we can observe its gravitational influence on visible matter. it explains how the expansion of the universe can be accelerating. we see lots of dark patches in the sky

Answer:

The anomalous expansion of water is an abnormal property of water whereby it expands instead of contracting when the temperature goes from 4°C to 0°C, and it becomes less dense. The density becomes less and less as it freezes because molecules of water normally form open crystal structures when in solid form.

Answer:

Frictional Force: Frictional force is the force caused by the relative motion of two surfaces that come into contact with each other.

Answer:

1. 60m

4. its speed is 20m/s . gravity is 10m/s . 20 ÷ 10 = 2 seconds after these 2 sec are over the velocity will be zero thus it would have fallen.

Explanation:

Am sorry these is what i could answer but i will try to research and get answers for the rest of the questions, hope this helps

Explanation:

it is a displacement reaction.

Answer:

A

Explanation:

If it is loooking for a proper question, it wants to know how fast the mouse was going

Answer: The answer for this is A.

Explanation: I know this cause i'm smart and totally didn't copy the other guy just to get points

Answer:

The atmosphere has frozen out into the polar ice caps and permafrost as Mars has cooled.

Explanation: Good luck box BrokenTag27

Answer:

B. Radio waves

Explanation:

Radio waves are transmitted easily through air. They do not cause damage if absorbed by the human body, and they can be reflected to change their direction. These properties make them ideal for communications.

Hope this helps!!

Answer:

B

Explanation:

Radio Waves

Answer:

480 Ohms for the calculations

Explanation:

For the calculations:

V = 120 and I = 0.25

V = IR

R = V/I

R = 120/0.25

R = 480 Ohms

For the sentences, I am so sorry, I do not have them yet!

I. The resistance which is needed to generate a current of 0.25 Ampere in the ceiling fan is 480 Ohms.

II. Since current is inversely proportional to the resistance in the electrical circuit, an increase in the current (larger currents) flowing into the electrical circuit of the ceiling fan would cause the resistance to decrease in magnitude at medium and high speeds.

Given the following data:

To calculate the resistance needed to generate that current, we would apply Ohm's law:

Ohm's law states that at constant temperature, the current flowing through an electrical circuit is directly proportional to the voltage (potential difference) applied across the two terminals of the electrical circuit and inversely proportional to the resistance in the electrical circuit.

Mathematically, Ohm's law is given by the formula;

[tex]V=IR[/tex]

Where;

Making R the subject of formula, we have:

[tex]R =\frac{V}{I}[/tex]

Substituting the given parameters into the formula, we have;

[tex]R=\frac{120}{0.25}[/tex]

Resistance, R = 480 Ohms

Since current is inversely proportional to the resistance in the electrical circuit, an increase in the current (larger currents) flowing into the electrical circuit of the ceiling fan would cause the resistance to decrease in magnitude at medium and high speeds.

In conclusion, the larger the current, the lower the resistance would be at both medium and high speeds.

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Answer:

Kepler's First Law: each planet's orbit about the Sun is an ellipse. The Sun's center is always located at one focus of the orbital ellipse. The Sun is at one focus. The planet follows the ellipse in its orbit, meaning that the planet to Sun distance is constantly changing as the planet goes around its orbit.

Answer:

Explanation:

Kepler 's first law - sometimes referred to as the law of ellipses - explains that planets are orbiting the sun in a path described as an ellipse. An ellipse can easily be constructed using a pencil, two tacks, a string, a sheet of paper and a piece of cardboard. Tack the sheet of paper to the cardboard using the two tacks.

The vectors point along the axis of rotation with a direction determined by an arrow.

There are two types of physical quantity one is a scaler and another one is a vector.

The quantity that requires only megnitude to define is known as the scalar quantity. While the vector quantities need both megnitude and the direction to define.

The vector quantity is represented by an arrow. The vectors point along the axis of rotation with a direction determined by an arrow.

The angular quantities L, omega, and alpha are vector quantities.

Hence arrow is the correct answer for the blank.

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The direction of the vectors of angular momentum and L, angular velocity omega and the mass alpha is determined using the right hand rule.

Righthand rule in physics states that, when we curl our right hand fingers, the direction of the angular momentum and velocity will be in the direction of thumb and curl of fingers determine the axis of rotation.

Angular momentum is a vector quantity defined as the product of moment of inertia and angular velocity where, the angular velocity ω is the rotational analogue of linear velocity i.e.. product of the linear velocity and radius of rotational path.

Therefore, the angular quantities L, angular velocity ω along the axis of rotation can be determined using the right hand rule. Where direction of thump represents the direction of vector components.

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Answer:

D

Explanation:

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Gravitational Potential Energy of an object is calculated by formula ~

[tex] \large\boxed{\sf P = mgh}[/tex]

where,

Now, let's calculate its potential energy ~

Answer:

Potential Energy of an object is calculated by formula:

Where,

Now, let's solve the question.

Given,

Now,

We know that,

Potential Energy (P.E)=mgh

[tex] = 3500 \times 10 \times 4[/tex]

[tex] = 3500 0\times 4[/tex]

[tex] =140000 joules [/tex]

[tex]\mathfrak{\blue{DisneyPrincess29}}[/tex]

The distance in which the spring is compressed is 1.065 m.

The given parameters;

Apply the principle of conservation of energy to determine the distance in which the spring is compressed.

[tex]K.E = W + U\\\\\frac{1}{2} mv^2 = \mu Fx \ + \ \frac{1}{2} kx^2\\\\\frac{1}{2}(4.2)(3.5)^2 = 0.25(4.2 \times 9.8)(x) \ + \frac{1}{2} (26)(x^2)\\\\25.725 = 10.29x \ + \ 13x^2\\\\13x^2 + 10.29x - 25.725 = 0\\\\[/tex]

solve the quadratic equation using formula method;

a = 13, b = 10.29,  c = -25.725

[tex]x = \frac{-b \ \ +/- \ \sqrt{b^2 - 4ac} }{2a} \\\\x = \frac{-(10.29) \ \ +/- \ \sqrt{(10.29)^2 \ - \ 4(13\times 25.725)} }{2(13)} \\\\x = 1.065 \ m, \ \ or \ -1.86 \ m[/tex]

choose positive distance, x = 1.065 m.

Thus, the distance in which the spring is compressed is 1.065 m.

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Answer:

you are very kind Po lang

The answer is D

I took the quiz lol

Answer:

if not sure sorry hope someone helps u❤️

Answer:

because of the gravity of the earth

Answer:

0.7 m between the balance point and Tiny

Explanation:

It's intuitive to say she sould be on the side the smaller mass is placed. How far from the balance point?

Let's call x that distance. and assume that the contraption is "oriented" so that being on the side with tiny (and teeny) gives you a positive distance from the balance point, and negative on the other side.

At equilibrium, the sum of all momentums (momenta?) will be zero:

[tex]67\times 1.4 +32\times x + 83 \times (-1.4) = 0\\32x -16(1.4) = 0 \rightarrow 2x=1.4 x= 0.7[/tex]

In layman's term, she has to be halfway between the balance point and Tiny.

Answer:

resistance of the metal conductor at different temperature

Explanation:

An experiment used to determine the resistance of a metallic conductor is the resistance of a metallic conductor at different temperatures.

Resistance is the property of a conductor to oppose the flow of charges through it which is numerically given as the ratio of the potential difference across its length to the current flowing through it.

Resistance of a metallic conductor is the measure of its opposition to the flow of electric current. Resistance is known to be directly proportional to the temperature which means as the temperature is increased, its resistance increases too and vice versa.

Resistance has an inverse relationship with the cross sectional area of ​​a metallic conductor, so if the resistance increases the cross sectional area decreases and vice versa.

Thus, an experiment used to determine the resistance of a metallic conductor is the resistance of a metallic conductor at different temperatures.

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Answer:

Balloon that an ocean diver takes to a pressure of 202 k Pa will get reduced in size that is the volume of the balloon will get reduced

Explanation:

When you pedal a bike with chains attached to it, the wheel spins as you exert force from your body into the pedaling. The chains are connected to an almost circular shape.

Contrary to popular assumption, using machines does not result in more work being done. They merely alter the method of operation. Machines make work easier by increasing the amount of force used, extending the distance over which the force is exerted, or changing the direction of the force.

Simple machines are helpful because they lessen effort or enable humans to execute things that would normally be beyond their capacity. The wheel and axle, pulley, inclined plane, screw, wedge, and lever are examples of simple devices that are frequently employed.

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Answer:

Solution given:

work done=340J

displacement(d)=75m

force[f]=?

we have

work done =Force*displacement

340=Force*75

Force=340/75

Force=4.5N

Given,

Work done = 340 J

Distance = 75 m

Force = work done / distance

Force = 340 / 75

Force = 4.533 Newton (N)

______

RainbowSalt2222

Answer:

calculate it by using formula w=m×g

The mass of an object if its weight on earth is 1150N is 117.347 kg.

The weight of an object is defined as the force that acts on the object due to gravity. Sometimes weight is defined as a vector quantity, the force of gravity acting on an object. Others define weight as a scalar quantity, the magnitude of the force of gravity.

It is gravitational force of attraction on an object which is caused by the presence of a massive second object like Earth or Moon. Weight is expressed by multiplying the mass times the acceleration due to gravity.

W=mg

Where, W= weight of the object

m= Mass of the object

g= Acceleration due to gravity i.e. [tex]9.8[/tex] [tex]m/s^2[/tex]

In above information,

W= 1150N

g= [tex]9.8[/tex] [tex]m/s^2[/tex]

Using the formula

m=W/g

m=1150/9.8

m=117.347 kg

Thus, the mass of an object if its weight on earth is 1150N is 117.347 kg.

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Answer:

it states that energy can either be gained or lost but it only changes its form.

Explanation:

for example:as a ball is still on the table it posses a potential energy of 100j and a k.e of 0j,as it falls it gains k.e so the midpoint the p.e is equal to the k.e (50j equally) as it approches the ground it completely gains k.e (100j) and the p.e is 0j.

total energy is 100j so it has been converted from p.e to k.e.

hope u have understood.

Answer: It was on between 7 and 7.30 and also between 8 and 8.30 (when the line on the graph goes up only). So it was on for an hour or 60 minutes

Answer:

Nuclear fission of heavy elements produces exploitable energy because the specific binding energy (binding energy per mass) of intermediate-mass nuclei with atomic numbers and atomic masses.

Explanation:

have a great day!! :)

Answer:

10m South East

simple subtract and ummmmmm.....