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4 years ago

Can an objects mechanical energy be equal to its gravitational potential energy

1 answer:

8 0

If an object falls, it gives up its gravitational potential energy. The gravitational force does work on it, and speeds it up. Its GPE is converted into kinetic energy. In the absence of friction, or any external force, the mechanical energy in a system is conserved.

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Options are upper left upper right bottom left bottom right for both problems please help!

polet [3.4K]

Answer:

(upper right) corner of the periodic table to the bottom left corner

6 0

3 years ago

A mixture consists of 28% oxygen, 14% hydrogen, and 58% nitrogen by volume. A sample of this mixture has a pressure of 4.0 atm i

stepladder [879]

Answer:

C) 1.3 mol

Explanation:

Using gas law we can find the initial moles of the sample of the mixture, as follows:

PV = nRT

PV / RT = n

Where P is pressure: 4.0atm

V is volume: 9.6L

R is gas constant: 0.082atmL/molK

T is absolute temperature: 300K

And n are moles of the gas

PV / RT = n

4.0atm*9.6L / 0.082atmL/molK300K = n

n = 1.56moles of the mixture of the gas are present into the 9.6L container

Now, 14% of this gas is hydrogen that was removed of the system, that is:

1.56mol*14% = 0.22 moles of hydrogen are removed.

Thus, moles of gas that remains in the container are:

1.56mol - 0.22mol = 1.34mol.

Right answer is:

6 0

3 years ago

Read 2 more answers

If acetic acid is the only acid that vinegar contains (ka=1.8×10−5), calculate the concentration of acetic acid in the vinegar.

kicyunya [14]

Ethanoic (Acetic) acid is a weak acid and do not dissociate fully. Therefore its equilibrium state has to be considered here.

$CH_{3}COOH \ \textless \ ---\ \textgreater \ H^{+} + CH_{3}COO^{-}$

In this case pH value of the solution is necessary to calculate the concentration but it's not given here so pH = 2.88 (looked it up)

pH = 2.88 ==> $[H^{+}]$ = $10^{-2.88}$ = 0.001 $moldm^{-3}$

The change in Concentration Δ $[CH_{3}COOH]$ = 0.001 $moldm^{-3}$

  CH3COOH H+ CH3COOH
Initial   $moldm^{-3}$      $x$ 0 0

Change $moldm^{-3}$ -0.001 +0.001 +0.001

Equilibrium $moldm^{-3}$ $x$ - 0.001 0.001 0.001


Since the $k_{a}$ value is so small, the assumption
$[CH_{3}COOH]_{initial} = [CH_{3}COOH]_{equilibrium}$ can be made.

$k_{a} = [tex]= 1.8*10^{-5} = \frac{[H^{+}][CH_{3}COO^{-}]}{[CH_{3}COOH]} = \frac{0.001^{2}}{x}$

Solve for x to get the required concentration.

note: 1.)Since you need the answer in 2SF don&t round up values in the middle of the calculation like I've done here.

2.) The ICE (Initial, Change, Equilibrium) table may come in handy if you are new to problems of this kind

Hope this helps!

8 0

4 years ago

In wich situation can a mixture always be called a solution

weeeeeb [17]

A mixture can always be called a solution when its homogeneous.

6 0

3 years ago

Read 2 more answers

The cell membrane responds to chemical signals from other cells A) true B) false

nataly862011 [7]

The answer would be A)true

8 0

4 years ago

Read 2 more answers