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sleet_krkn [62]
3 years ago
6

Darwin believed that emotional expressions began as ________ that came to have evolutionary value because they ________. Select

one: a. physiological reactions; increased the efficiency of bodily reactions b. communication devices; increased the efficiency of bodily reactions Incorrect c. physiological reactions; convey emotional states to other members of the species d. random mutations; convey expectations to other members of the species
Physics
1 answer:
Strike441 [17]3 years ago
5 0

Answer:

c. physiological reactions; convey emotional states to other members of the species

Explanation:

Darwin believed that emotional expressions began as physiological reactions that came to have evolutionary value because they convey emotional states to other members of the species. These reactions are used by many different types of species to convey various things.

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2. When the pump removed the air in<br> the bell, the balloon<br> contracted<br> expanded
IRINA_888 [86]

When the pump removed the air in  the bell, the balloon expanded.

<u>Option: B</u>

<u>Explanation:</u>

In order to construct our own environment in the glass jar known as bell jar system, which can be used to explore and consider our larger environment on Earths, for an instance. Here a glass jar that hinges on an airtight rubber basis i.e seals appropriately. At the top of the jar, a bung is connected to it which passed via a metal tube. It has an adjacent flexible tube that goes to a hand vacuum pump and the best hand-powered pump was made with a wine preserver.

When the pump extracts the air from the bell jar, the pressure inside the balloon naturally decreases. The balloon usually has a air pressure around it, which restricts its size, but when this air is extracted and the pressure around it decreases the gas in the balloon will expand and the balloon seems to be inflating. When you release the air back into the bell jar, it will once again compress back to its actual size.

8 0
3 years ago
Something that has many particles in a small space would have a ————- density
Diano4ka-milaya [45]

Answer:

a high density i believe

Explanation:

4 0
3 years ago
Read 2 more answers
You pull straight up on the string of a yo-yo with a force 0.35 N, and while your hand is moving up a distance 0.16 m, the yo-yo
jarptica [38.1K]

Answer:

a) 0.138J

b) 3.58m/S

c) (1.52J)(I)

Explanation:

a) to find the increase in the translational kinetic energy you can use the relation

\Delta E_k=W=W_g-W_p

where Wp is the work done by the person and Wg is the work done by the gravitational force

By replacing Wp=Fh1 and Wg=mgh2, being h1 the distance of the motion of the hand and h2 the distance of the yo-yo, m is the mass of the yo-yo, then you obtain:

Wp=(0.35N)(0.16m)=0.056J\\\\Wg=(0.062kg)(9.8\frac{m}{s^2})(0.32m)=0.19J\\\\\Delta E_k=W=0.19J-0.056J=0.138J

the change in the translational kinetic energy is 0.138J

b) the new speed of the yo-yo is obtained by using the previous result and the formula for the kinetic energy of an object:

\Delta E_k=\frac{1}{2}mv_f^2-\frac{1}{2}mv_o^2

where vf is the final speed, vo is the initial speed. By doing vf the subject of the formula and replacing you get:

v_f=\sqrt{\frac{2}{m}}\sqrt{\Delta E_k+(1/2)mv_o^2}\\\\v_f=\sqrt{\frac{2}{0.062kg}}\sqrt{0.138J+1/2(0.062kg)(2.9m/s)^2}=3.58\frac{m}{s}

the new speed is 3.58m/s

c) in this case what you can compute is the quotient between the initial rotational energy and the final rotational energy

\frac{E_{fr}}{E_{fr}}=\frac{1/2I\omega_f^2}{1/2I\omega_o^2}=\frac{\omega_f^2}{\omega_o^2}\\\\\omega_f=\frac{v_f}{r}\\\\\omega_o=\frac{v_o}{r}\\\\\frac{E_{fr}}{E_{fr}}=\frac{v_f^2}{v_o^2}=\frac{(3.58m/s)}{(2.9m/s)^2}=1.52J

hence, the change in Er is about 1.52J times the initial rotational energy

5 0
2 years ago
Read 2 more answers
A person is singing in the shower. They notice that as certain notes become very loud, the shower walls vibrate. Which statement
AysviL [449]

Answer:

the note is one of the harmonic frequencies for the shower.

I just took the quiz, this is correct. Hope this helps:)

Explanation:

8 0
3 years ago
What are the three most important types of units in radiobiology? Explain the meaning of each.
Rom4ik [11]

Answer:

Most adverse health effects of radiation exposure may be grouped in two general categories:

deterministic effects (harmful tissue reactions) due in large part to the killing/ malfunction of cells following high doses; and

stochastic effects, i.e., cancer and heritable effects involving either cancer development in exposed individuals owing to mutation of somatic cells or heritable disease in their offspring owing to mutation of reproductive (germ)

4 0
2 years ago
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