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3 years ago

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What is the pH scale used for? a. Measures hydroxide ion concentration (strength of the acid or base) b. Measures hydronium ion

concentration (strength of the acid or base)

1 answer:

Talja [164]3 years ago

7 0

The correct answer is a. Measures hydroxide ion concentration (strength of the acid or base) because when you look at the scientific definition of the use of a PH scale it says... "Acidity is the amount of hydrogen protons present in a solution and basicity is the amount of hydroxide ions present in a solution. The pH scale measures how acidic or basic a substance is. It ranges from 0 to 14. A pH of 7 is neutral."

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A block (mass = 61.2 kg) is hanging from a massless cord that is wrapped around a pulley (moment of inertia = 1/2MR2 kg · m2, wh

kolezko [41]

Answer:

The angular velocity is $w = 53.35 \ rounds /minute$

Explanation:

From the question we are told that

The mass of the block is $m = 61.2kg$

The of the pulley is $M = 14.2 kg$

The radius of the pulley is $R = 1.5m$

The radius of the cord around the pulley is $r = 1.5 m$

The distance of the block to the floor is $d = 8.0 m$

From the question we are told that the moment of inertia of the pulley is

$I = \frac{1}{2} MR^2 kg \cdot m^2$

Substituting value

$I = \frac{1}{2} * 14.2 * (1.5)^2$

$I = 15.975 kg \cdot m^2$

Using the Newtons law we can express the force acting on the vertical axis as

$ma = mg -T$

=> $T = mg -ma$

Now when the pulley is rotated that torque generated on the massless cord as a r result of the tension T and the radius of the cord around the pulley is mathematically represented as

$\tau = I \alpha$

Here $\alpha$ is the angular acceleration

Here $\tau$ is the torque which can be equivalent to

$\tau = T r$

Substituting this above

$Tr = I \alpha$

Substituting for T

$(mg - ma ) r = I\ r \alpha$

Here $a$ is the linear acceleration which is mathematically represented as

$a = r\alpha$

$(mg - m(r\alpha ) ) r = I\ r \alpha$

$mgr = I\alpha + m(r\alpha ) r$

$mgr = \alpha [ I + mr^2]$

making $\alpha$ the subject

$\alpha = \frac{mgr}{I -mr ^2}$

Substituting values

$\alpha = \frac{61.2 * 1.5 * 9.8}{15.975 + (61.2 ) * (1.5)^2}$

$\alpha =5.854 rad /s^2$

Now substituting into the equation above to obtain the acceleration

$a = 5.854 * 1.5$

$a=8.78 m/s^2$

This acceleration is $a = \frac{v}{t}$

and v is the linear velocity with is mathematically represented as

$v = \frac{d}{t}$

Substituting this into the formula acceleration

$a = \frac{d}{t^2}$

making t the subject

$t = \sqrt{\frac{d}{a} }$

substituting value

$t = \sqrt{\frac{8}{8.78}}$

$t = 0.9545 \ s$

Now the linear velocity is

$v = \frac{8}{0.9545}$

$v = 8.38 m/s$

The angular velocity is

$w = \frac{v}{r}$

So

$w = \frac{8.38}{1.5}$

$w = 5.59 rad/s$

Generally 1 radian is equal to 0.159155 rounds or turns

So 5.59 radian is equal to x

Now x is mathematically obtained as

$x = \frac{5.59 * 0.159155}{1}$

$= 0.8892 \ rounds$

Also

60 second = 1 minute

So 1 second = z

Now z is mathematically obtained as

$z = \frac{ 1}{60}$

z $= 0.01667 \ minute$

Therefore

$w = \frac{0.8892}{0.01667}$

$w = 53.35 \ rounds /minute$

8 0

3 years ago

Which factor would reduce the size of a forest population

zhuklara [117]

C. Lack of mates. If they cannot reproduce enough, their size will reduce.

7 0

3 years ago

Read 2 more answers

NEED IT ASAP PLEASE 3 examples of how we use physics in our everyday life. Please explain throughly.

Flauer [41]

Answer:

Alarm Clock. The buzzing sound of an alarm clock helps you wake up in the morning as per your schedule. The sound is something that you can’t see, but hear or experience.
Cell Phones Cellphones have become like Oxygen gas in modern social life. Hardly, anyone would have been untouched by the effects of a cell phone. Whether conveying any urgent message or doing incessant gossips, cellphones are everywhere. But do you know how does a cell phone work? It works on the principle of electricity and the electromagnetic spectrum, undulating patterns of electricity and magnetism.
Walking.Now, when you get ready for your office/school, whatever medium of commutation is, you certainly have to walk up to a certain distance. You can easily walk is just because of Physics. While you have a walk in a park or on a tar road, you have a good grip without slipping because of a sort of roughness or resistance between the soles of your shoes and the surface of the road.

Explanation:

physical is related to things perceived through the senses as opposed to the mind; tangible or concrete.

3 0

3 years ago

Can someone help me with these questions plz

Korolek [52]

Im not 100% on these but i can try

1. A compound is made up of elements and their different atoms

2.

A. salt- compound (NaCl) is two elements Na (sodium) and Cl (chloride?)

B. Nitrogen- element its on the periodic table

C. Helium- element its on the periodic table

D. Water- compound (H2O) two elements hydrogen and oxygen

3. element, compound, compound, element

Hope this helps

8 0

3 years ago

1. What kind of light phenomena happen due to the refraction of light upon hitting the small crystals that make up cirrus or cir

Rama09 [41]

1. The light phenomena happen due to the refraction of light upon hitting the small crystals that make up cirrus or cirrostratus clouds is called Sundogs.

2.A light phenomena which are formed when light passes through clouds and strikes the ice crystals in them is called Halos.

3.A light phenomenon formed from the combination of several light properties like refraction, reflection, and dispersion is Rainbow.

4. Rainbow are created after a rain shower and Sun light.

5. A visible accumulations of tiny water droplets or ice crystals.

in the Earth’s atmosphere are called Clouds.

6. There are seven colors in a rainbow.

7. The kind of rainbows are formed when light strikes small raindrops with almost the same size are Supernumerary rainbows.

8.The kind of rainbows are formed when two inner reflections are done instead of one; this causes the reversal of colors in a secondary rainbow in comparison to a primary rainbow are Secondary rainbows.

9. A reflective surface that is curved inward and away from the light source is concave mirror.

10. The kind of mirror are curved outward like the bottom

of a spoon is convex mirror.

<h3>What is reflection?</h3>

When a light strikes on a shiny surface, it reflects back the light ray in the same medium. The phenomenon is called reflection and the ray is called the reflected ray.

Thus, all the questions are answered.

Learn more about reflection.

brainly.com/question/2254222

#SPJ1

8 0

1 year ago