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3 years ago

Astronomers believe that cosmic background radiation formed:

1 answer:

5 0

The assumption that the cosmic microwave background
is the remnant of the environment at the time of the big bang
or very shortly after it explains very well what we observe now.
So it is the current prevailing theory. "Believe" is not involved.

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The force of ________ is the force at which the earth attracts another object towards itself.

antiseptic1488 [7]

<span>The correct option is C. Gravity, and the complete sentence is: "The force of gravity is the force at which the Earth attracts another object towards itself". In fact, the force of gravity between two objects is given by
</span> $F= \frac{Gm_1m_2}{r^2}$ <span>
where G is the gravitational constant, m1 and m2 the masses of the two objects, r their separation. If we take the Earth as one of the two objects, then m1 represents the Earth's mass, m2 the mass of the object and r the distance between the center of Earth and the object, and F is the gravitational force at which the Earth attracts the object.</span>

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3 years ago

Read 2 more answers

When using a liquid as a solvent, what could be the state(s) of matter of the solute?

sattari [20]

Answer:

Explanation:

it can be a gas like carbon dioxide in soda

it can be liquid like alcohol in water

it can be solid like sugar and salt

8 0

3 years ago

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Henry, whose mass is 95 kg, stands on a bathroom scale in an elevator. The scale reads 830 N for the first 3.8 s after the eleva

Delicious77 [7]

Answer:

v= 4.0 m/s

Explanation:

When standing on the bathroom scale within the moving elevator, there are two forces acting on Henry's mass: Normal force and gravity.
Gravity is always downward, and normal force is perpendicular to the surface on which the mass is located (the bathroom scale), in upward direction.
Normal force, can adopt any value needed to match the acceleration of the mass, according to Newton's 2nd Law.
Gravity (which we call weight near the Earth's surface) can be calculated as follows:

$F_{g} = m*g = 95 kg * 9.8 m/s2 = 930 N (1)$

According to Newton's 2nd Law, it must be met the following condition:

$F_{net} = F_{g} -F_{n} = m*a\\ F_{net} = 930 N - 830 N = 100 N = 95 Kg * a$

As the gravity is larger than normal force, this means that the acceleration is downward, so, we choose this direction as the positive.

Solving for a, we get:

$a =\frac{F_{net} }{m} =\frac{100 N}{95 kg} = 1.05 m/s2$

We can find the speed after the first 3.8 s (assuming a is constant), applying the definition of acceleration as the rate of change of velocity:

$v_{f} = a* t = 1.05 m/s * 3.8 m/s = 4.0 m/s$

Now, if during the next 3.8 s, normal force is 930 N (same as the weight), this means that both forces are equal each other, so net force is 0.
According to Newton's 2nd Law, if net force is 0, the object is either or at rest, or moving at a constant speed.
As the elevator was moving, the only choice is that it is moving at a constant speed, the same that it had when the scale was read for the first time, i.e., 4 m/s downward.

3 0

4 years ago

In a given chemical reaction, the energy of the products is less than the energy of the reactants. Which statements is true for

Inessa05 [86]

Answer:It is an Endothermic reaction

Explanation:

Exothermic reaction

An exothermic reaction is one that releases energy in the form of heat or light.

Endothermic reaction

An endothermic reaction is one that absorbs energy in the form of heat or light.

7 0

3 years ago

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WILL MARK BRAINLIEST!!!!!!!!!!!!!!!!!!

stepan [7]

*FRICTIONAL FORCE* in the opposite direction of the way Bobby is pushing.
Friction is a force which varies but it is always opposing the direction of motion.

*APPLIED FORCE* is the force that Bobby is pushing with.
An applied force is literally the force that is applied to an object.

*WEIGHT FORCE* is also called the force of gravity. It is straight downward.
It is the weight of the object multiplied by the force of gravity. If the TV weighed 100kg, acceleration is always 9.81 m/s^2, so the weight force would be 981 N.

*NORMAL FORCE* is the force which is holding the TV above ground. The ground supplies a force upward against the TV.
Normal force is just the force that prevents the TV from falling through the ground. We don't normally realize it in our everyday life, but the floor must hold everything up because gravity is always "pushing" against it.

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3 years ago