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2 years ago

A student heats a liquid on a burner. What happens to the portion of liquid that first begins to warm? What all applys

2 answers:

5 0

For water, as the temperature goes up the density of the liquid water decreases therefore it becomes less dense so it tends to rise upward. And since the temperature here is higher, heat flows from the higher temperature to the lower so it releases energy to the environment. Therefore, the correct statements are 2, 3 and 5.

sineoko [7]2 years ago

5 0

Answer:

It becomes less dense.

It absorbs energy from the environment.

It rises upward.

Explanation:

Took the test!

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Which best describes nuclear fusion?

MrMuchimi

Answer:

The statement that best describes nuclear fusion is;

Nuclei combine to form a heavier nucleus, releasing energy

Explanation:

In nuclear fusion, we have the reaction of the nuclei of two or more atoms coming together (combining) to form heavier elements and subatomic particles such as protons and neutrons accompanied by the release or absorption in energy depending on the difference between the mass of the reactants and the products

Some nuclear fusion reaction require an input of energy and such reactions are therefore not spontaneous

The best option is nuclei (two or more nuclei) combine to form a heavier nucleus, releasing energy.

5 0

2 years ago

Read 2 more answers

A person weighing 0.70 kn rides in an elevator that has an upward acceleration of 1.5 m/s2. what is the magnitude of the normal

creativ13 [48]

First of all, we can find the mass of the person, since we know his weight W:
$W=mg=0.70 kN=700 N$
And so
$m= \frac{W}{g}= \frac{700 N}{9.81 m/s^2}=71.4 kg$

We know for Newton's second law that the resultant of the forces acting on the person must be equal to the product between the mass and the acceleration a of the person itself:
$\sum F = ma$
There are only two forces acting on the person: his weight W (downward) and the vincular reaction Rv of the floor against the body (upward). So we can rewrite the previous equation as
$R_v -W = ma$
We know the acceleration of the system, $a=1.5 m/s^2$ (upward, so with same sign of Rv), so we can solve to find the value of Rv, the normal force exerted by the elevator's floor on the person:
$R_v = ma+W=(71.4 kg)(1.5 m/s^2)+700 N =807N$

8 0

2 years ago

As a blacksmith heats a piece of iron, the iron glows red, then yellow, then white. The iron provides a demonstration of which p

Nitella [24]

The answer is D. Blackbody radiation. The piece of iron glows red because its temperature is around 1000 K, then yellow because its temperature is around 2800 K, and then white because its temperature is around 5500K. This shows that the spectrum of the radiation is determined by absolute temperature, as when the temperature of a blackbody radiator increases, the peak of the radiation curve moves to shorter wavelengths.

6 0

2 years ago

Two identical objects A and B fall from rest from different heights to the ground. If object B takes twice as long as A to reach

aivan3 [116]

I believe this ratio is 4:1 due to the inverse square law

4 0

2 years ago

Read 2 more answers

If a sound with frequency fs is produced by a source traveling along a line with speed vs. If an observer is traveling with spee

Alexus [3.1K]

Answer:

457.81 Hz

Explanation:

From the question, it is stated that it is a question under Doppler effect.

As a result, we use this form

fo = (c + vo) / (c - vs) × fs

fo = observed frequency by observer =?

c = speed of sound = 332 m/s

vo = velocity of observer relative to source = 45 m/s

vs = velocity of source relative to observer = - 46 m/s ( it is taking a negative sign because the velocity of the source is in opposite direction to the observer).

fs = frequency of sound wave by source = 459 Hz

By substituting the the values to the equation, we have

fo = (332 + 45) / (332 - (-46)) × 459

fo = (377/ 332 + 46) × 459

fo = (377/ 378) × 459

fo = 0.9974 × 459

fo = 457.81 Hz

7 0

2 years ago