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3 years ago

Which statement best explains why so many fossils look different from the millions of species currently living on Earth?

Chemistry

2 answers:

lianna [129]3 years ago

3 0

B. Most species that have lived on earth are now extinct. Ap3x

Nana76 [90]3 years ago

3 0

Answer:

Explanation:

Most species that have lived on Earth are now extinct

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A P E X

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Kelli and Jarvis are members of the stage crew for the Variety Show. Between acts, they must quickly move a Baby Grand Piano ont

Marianna [84]

If Kelli and Jarvis maintain a forward force of 524 N for 1.44 seconds on a 158-kg piano, the acceleration will be 0.671 m/s² and the final velocity will be 0.966 m/s.

Kelli and Jarvis exert a force of 524 N on a 158- kg (m) piano.

The friction force, which opposes this force, is 418 N.

The net force (F) is the difference between both forces.

F = 524 N - 418 N = 106 N

We can calculate the acceleration (a) of the piano using Newton's second law of motion.

<h3>What is Newton's second law of motion?</h3>

Newton's second law of motion states that the acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force and inversely proportional to the mass of the object.

a = F/m = 106 N/158kg = 0.671 m/s²

The piano start from rest (u = 0 m/s) and moves with an acceleration of 0.671 m/s² for 1.44 s.

We can calculate its final velocity (v) using the following kinematic equation.

v = u + a × t

v = 0 m/s + 0.671 m/s² × 1.44 s = 0.966 m/s

If Kelli and Jarvis maintain a forward force of 524 N for 1.44 seconds on a 158-kg piano, the acceleration will be 0.671 m/s² and the final velocity will be 0.966 m/s.

Learn more about Newton's second law of motion here: brainly.com/question/10673278

3 0

3 years ago

In order to complete his research project, Roger needs to make a mixture of 86 mL of a 36% acid solution from a 39% acid

Zina [86]

The volume of the 39% acid solution that Roger needs to use to make a mixture of 86 mL of a 36% acid solution is 74.27 mL.

The mixture of the acids solutions is given by:

$CV = C_{1}V_{1} + C_{2}V_{2}$ (1)

Where:

C: is the concentration if the mixture = 36%

V: is the total volume of the mixture = 86 mL

C₁: is the concentration of acid 1 = 39%

V₁: is the volume if acid 1 =?

C₂: is the concentration of acid 2 = 17%

V₂: is the volume of acid 2

The sum of V₁ and V₂ must be equal to V, so:

$V = V_{1} + V_{2}$

$V_{2} = V - V_{1}$ (2)

By entering equation (2) into (1), we have:

$CV = C_{1}V_{1} + C_{2}(V - V_{1})$

$36\%*86 mL = 39\%*V_{1} + 17\%(86 mL - V_{1})$

Changing the percent values to decimal ones:

$0.36*86 mL = 0.39*V_{1} + 0.17(86 mL - V_{1})$

Now, by solving the above equation for V₁:

$V_{1} = 74.27 mL$

Therefore, the volume of the 39% acid solution is 74.27 mL.

To learn more about mixture and solutions, go here: brainly.com/question/6358654?referrer=searchResults

I hope it helps you!

7 0

3 years ago

Read 2 more answers

dedylja [7]

Answer:

It looked like the continents fit together like puzzle pieces

Could I Maybee get brainlest if someone else answers?

7 0

2 years ago

To determine the concentration of SO4 2– ion in a sample of groundwater, 100.0 mL of the sample is titrated with 0.0250 M Ba(NO3

Brrunno [24]

Answer:

1.87x10⁻³ M SO₄²⁻

Explanation:

The reaction of SO₄²⁻ with Ba²⁺ (From Ba(NO₃)₂) is:

SO₄²⁻(aq) + Ba²⁺(aq) → BaSO₄(s)

<em>Where 1 mole of SO₄²⁻ reacts per mole of Ba²⁺</em>

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To reach the end point in this titration, we need to add the same moles of Ba²⁺ that the moles that are of SO₄²⁻.

Thus, to find molarity of SO₄²⁻ we need to find first the moles of Ba²⁺ added (That will be the same of SO₄²⁻). And as the volume of the initial sample was 100mL we can find molarity (As ratio of moles of SO₄²⁻ per liter of solution).

<em>Moles Ba²⁺:</em>

7.48mL = 7.48x10⁻³L ₓ (0.0250moles / L) = 1.87x10⁻⁴ moles of Ba²⁺ = Moles of SO₄²⁻

<em>Molarity SO₄²⁻:</em>

As there are 1.87x10⁻⁴ moles of SO₄²⁻ in 100mL = 0.1L, molarity is:

1.87x10⁻⁴ moles of SO₄²⁻ / 0.1L =

8 0

3 years ago

Identify the cfc with the shortest atmospheric lifetime

goldenfox [79]

CFC-11 is typically the CFC with the shortest atmospheric lifetime.

5 0

3 years ago