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3 years ago

Which of these statements is true?

2 answers:

7 0

B). Some elements found in nature exist as molecules.
That is, their atoms travel around in bound pairs.
Examples are Hydrogen, Oxygen, and Nitrogen.

A). No. Without atoms, you can't make a molecule.

C). No. A compound is a chemical combination of two or more elements.

D). No. An atom is the smallest unit of ONE single element.

Oduvanchick [21]3 years ago

5 0

Hello, your answer is, C. Some compounds include only one type of element.

I hope it helped!

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2. nakabuti ba sa mga bansa sa kanlurang asya ang sistemang mandato na ipinatupad ng mga bansang kanluranin

Vilka [71]

yes o=====/::::::::::::::::>

8 0

2 years ago

You are spinning a rock, of mass 0.75 kg, at the end of a string of length 0.86m in a vertical circle in uniform circular motion

Nina [5.8K]

Answer:

v (minimum speed) = 2.90 m/sec.

$\\ \\ maximum speed (v)= 6.57 m/sec.\\$

Maximum value of speed will occur at lowest point of vertical circle.

Explanation:

a) What minimum speed is necessary so that there is no tension in the string at the top of the circle but the rock stays in the same circular path?

Using the force balance expression at the top of the circle,

Gravitational Force + Tension force = Centrifugal force

$m*g + T = m*v^2/R$

Given that : T = 0

R = length of string = 0.86 m

mass of the spinning rock = 0.75 kg

$v = \sqrt{g*R}$

$v = \sqrt{9.81*0.86}$

v (minimum speed) = 2.90 m/sec.

b) what is the maximum speed the rock can have so that the string does not break?

Here the force balance at bottom of circle is represented by the illustration:

$T = m*g + m*v^2/R$

Given that:

maximum tension T = 45 N

maximum speed v = ??

mass m = 0.75 kg

∴

$45 - 0.75*9.81 = 0.75*\frac{v^2}{0.86} \\\\v^2 = 0.86*(45 - 0.75*9.81)/0.75 \\ v = \sqrt{0.86*(45 - 0.75*9.81)/0.75\\ maximum speed (v)= 6.57 m/sec.\\$

At what point in the vertical circle does this maximum value occur?

Maximum value of speed will occur at lowest point of vertical circle.

This is so because at the lowest point; the tension in string will be maximum.

4 0

2 years ago

Will give brainiest to best answer

Gala2k [10]

Answer:

Explanation:

6 0

2 years ago

Can someone help me with 1-2

ira [324]

Can't really plot a graph here for question 1.

2a) The car speeds up from A to B. The car travels at a constant speed from B to C. The car slows down to a stop from C to D.

b) From the graph, at 10 seconds, the car is moving at 20 m/s.

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3 years ago

Based on the most widely accepted scientific explanation, elements began to form shortly after the big bang. Which of the follow

worty [1.4K]

Big Bang is a theory that, as stated above, has grown to become widely acceptable scientific explanation of the origin of things. Research would say that according to this theory, the Earth originated billion years ago through an explosive of a highly energized point.

Through this explosion, the elements were formed. However, only the lightest of the elements including hydrogen and helium, with traces of lithium and beryllium. From the choices, the answer would have to be the second choice, helium.

Answer: B. helium

5 0

3 years ago

Read 2 more answers