Help me please thank you

What is a way of transforming energy by exerting a force over distance?

xz_007 [3.2K]

Answer:

a. Work

Explanation:

If you apply a force over a given distance - you have done work. Work = Change in Energy. If an object's kinetic energy or gravitational potential energy changes, then work is done. The force can act in the same direction of motion.

8 0

3 years ago

Read 2 more answers

What is the pH of a mixture of 0.042 M NaH2PO4 and 0.058 M Na2HPO4? Hint: The pKa of phosphate is 6.86.

AlekseyPX

Answer:

The pH value of the mixture will be 7.00

Explanation:

Mono and disodium hydrogen phosphate mixture act as a buffer to maintain pH value around 7. Henderson–Hasselbalch equation is used to determine the pH value of a buffer mixture, which is mathematically expressed as,

$pH=pK_{a} + log(\frac{[Base]}{[Acid]})$

According to the given conditions, the equation will become as follow

$pH=pK_{a} + log(\frac{[Na_{2}HPO_{4} ]}{[NaH_{2}PO_{4}]})$

The base and acid are assigned by observing the pKa values of both the compounds; smaller value means more acidic. NaH₂PO₄ has a pKa value of 6.86, while Na₂HPO₄ has a pKa value of 12.32 (not given, but it's a constant). Another more easy way is to the count the acidic hydrogen in the molecular formula; the compound with more acidic hydrogens will be assigned acidic and vice versa.

Placing all the given data we obtain,

$pH=6.86 + log(\frac{0.058}{0.042})$

$pH=7.00$

5 0

3 years ago

Acetaminophen is the generic name of the pain reliever in Tylenol and some other headache remedies- The compoundhas the molecula

slega [8]

Answer: The mass percentage of carbon element is 63.57 %, hydrogen element is 5.96 %, nitrogen element is 9.28 % and oxygen element is 21.19 %

Explanation:

We are given:

A chemical compound having chemical formula of $C_8H_9NO_2$ . This compound is made by the combination of carbon, hydrogen, nitrogen and oxygen elements.

1 mole of acetaminophen contains 8 moles of carbon atom, 9 moles of hydrogen atom, 1 mole of nitrogen atom and 2 moles of oxygen atom

Mass of carbon element = $(8\times 12)=96g/mol$

Mass of hydrogen element = $(9\times 1)=9g/mol$

Mass of nitrogen element = $(1\times 14)=14g/mol$

Mass of oxygen element = $(2\times 16)=32g/mol$

Mass of the compound = 151 g/mol

To calculate the percentage composition of an element in a compound, we use the equation:

$\%\text{ composition of an element}=\frac{\text{Mass of element}}{\text{Mass of compound}}\times 100$ ........(1)

For carbon element:

Putting values in equation 1, we get:

$\% \text{ composition of carbon element}=\frac{96}{151}\times 100\\\\\% \text{ composition of carbon element}=63.57\%$

For hydrogen element:

Putting values in equation 1, we get:

$\% \text{ composition of hydrogen element}=\frac{9}{151}\times 100\\\\\% \text{ composition of hydrogen element}=5.96\%$

For nitrogen element:

Putting values in equation 1, we get:

$\% \text{ composition of nitrogen element}=\frac{14}{151}\times 100\\\\\% \text{ composition of nitrogen element}=9.28\%$

For oxygen element:

Putting values in equation 1, we get:

$\% \text{ composition of oxygen element}=\frac{32}{151}\times 100\\\\\% \text{ composition of oxygen element}=21.19\%$

Hence, the mass percentage of carbon element is 63.57 %, hydrogen element is 5.96 %, nitrogen element is 9.28 % and oxygen element is 21.19 %

6 0

3 years ago

An ion has a mass number of 65, 36 neutrons, and a charge of +1 . Identify the element symbol, and determine the number of proto

docker41 [41]

Answer:

Element symbol Cu

Number of protons 29

Number of electrons 28

Explanation:

To get the element symbol, we need the name of the element. To correctly identify the name of the element, we need the proton number.

Now the mass number is 65 and the number of neutrons is 36. The number of protons is this the mass number minus the number of neutrons. This equals 65 - 36 = 29 protons.

The element with 29 protons is copper Cu.

Now to get the number of electrons, for an electrically neutral atom , the number of electrons equals the number of protons. But here, the atom is not electrically neutral anymore as it has now formed a univalent positive ion of +1.

To form a positive ion, you have to do so by losing electrons. The atom in question here has just lost one electron. Thus, our of the 29, it is left with only 28 electrons.

8 0

3 years ago

Read 2 more answers

answer the following: a. Explain how a pulley changes the amount of force needed to lift an object. b. do all pulleys change the

Natalija [7]

If you want to lift something that weighs 100kg, you have to pull down with a force equivalent to 100kg, which is 1000N (newtons). I hope this helps, please mark brainiest if it does. I will attach a picture I found off the internet to further help you :)
(There are like 1,000,000,000,000,000,000,000 other ways I could have put that, to make it sound less creepy, I could just edit it now instead of writing this huge thing... oh well lol)

8 0

3 years ago