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4 years ago

Please help me with this question someone

Physics

2 answers:

Gekata [30.6K]4 years ago

8 0

From the answers provided, I believe the possible answer would be the last option, silicon, oxygen, and one or more metals. Here's my reasoning: the most abundant mineral group found in the Earth's crust is the silicate group. The silicate materials contain both oxygen and silicon. Silicates are the most common minerals in the rock-formation process, and it has, in fact, been estimated that they make up 75 to 90 percent of the Earth's crust. From this piece of evidence, I can guess that the answer will possibly be D, silicon, oxygen, and one or more metals.
It should also be noted that the additional elements that combine with the silicon-oxygen tetrahedron are involved with the other elements commonly found in the Earth's crust and mantle. They are aluminum, calcium, iron, magnesium, potassium and sodium.

Marianna [84]4 years ago

5 0

The last option, silicon, oxygen, and one or more metals

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_____ are group of tissue working together to perform a certain job.

Alja [10]

Answer:

organ

Explanation:

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3 years ago

A marathon runner completes a 42.238 km course in 2 h, 31 min, and 46 s . There is an uncertainty of 29 m in the distance run an

icang [17]

Answer:

The percentage uncertainty in the average speed is 0.10% (2 sig. fig.)

Explanation:

Consider the formula for average speed $\bar{v}$ .

$\displaystyle \bar{v} = \frac{s}{t}$ ,

where

$s$ is the total distance, and
$t$ is the time taken.

The percentage uncertainty of a fraction is the sum of percentage uncertainties in

the numerator, and
the denominator.

What are the percentage uncertainties in $s$ and $t$ in this question?

The unit of the absolute uncertainty in $s$ is meters. Thus, convert the unit of $s$ to meters:

$s = \rm 42.238\;km = 42.238\times 10^{3}\;m$ .

$\begin{aligned}\displaystyle \text{Percentage Uncertainty in }s &= \frac{\text{Absolute Uncertainty in } s}{\text{Measured Value of }s}\times 100\% \\ &=\rm\frac{29\; m}{42.238\times 10^{3}\;m}\times 100\%\\ &= 0.0687\%\end{aligned}$ .

The unit of the absolute uncertainty in $t$ is seconds. Convert the unit of $t$ to seconds:

$t = \rm 2\times 3600 + 31\times 60 + 46 = 9106\;s$

Similarly,

$\begin{aligned}\displaystyle \rm \text{Percentage Uncertainty in }t &= \frac{\text{Absolute Uncertainty in }t}{\text{Measured Value of }t}\times 100\% \\ &=\rm\frac{46\; s}{9106\;s}\times 100\%\\ &= 0.0329\%\end{aligned}$ .

The average speed $\bar{v}$ here is a fraction of $s$ and $t$ . Both $s$ and $t$ come with uncertainty. The percentage uncertainty in $\bar{v}$ will be the sum of percentage uncertainties in $s$ and $t$ . That is:

$\text{Percentage Uncertainty in }\bar{v}\\=(\text{Percentage Uncertainty in } s) + (\text{Percentage Uncertainty in } t)\\ = 0.0687\% + 0.0329\%\\ = 0.010\%$ .

Generally, keep

two significant figures for percentage uncertainties that are less than 2%, and
one for those that are greater than 2%.

The percentage uncertainty in $\bar{v}$ here is less than 2%. Thus, keep two significant figures. However, keep more significant figures than that in calculations to make sure that the final result is accurate.

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4 years ago

Katie rolls a toy car off the end of a table. Which path will the car follow when it leaves the table? A. B. C. D.

Dimas [21]

Answer:

parabolic path

Explanation:

As the cart reaches the end of the table with a horizontally directed velocity (only horizontal component), the cart will follow a parabolic path given by the combined action of:

(1) kinematic equation for motion under constant velocity in the horizontal direction (linear expression in terms of time), and

(2) kinematic equation for motion under constant acceleration (that of gravity) in the vertical direction (quadratic expression in terms of time)

8 0

3 years ago

Read 2 more answers

A rocket sled for testing equipment under large accelerations starts at rest and accelerates according to the expression a = (3.

mash [69]

Answer:

9.6 m

Explanation:

This is a case of motion under variable acceleration . So no law of motion formula will be applicable here. We shall have to integrate the given equation .

a = 3.6 t + 5.6

d²x / dt² = 3.6 t + 5.6

Integrating on both sides

dx /dt = 3.6 t² / 2 + 5.6 t + c

where c is a constant.

dx /dt = 1.8 t² + 5.6 t + c

when t = 0 , velocity dx /dt is zero

Putting these values in the equation above

0 = 0 +0 + c

c = 0

dx /dt = 1.8 t² + 5.6 t

Again integrating on both sides

x = 1.8 t³ / 3 + 5.6 x t² /2 + c₁

x = 0.6 t³ + 2.8 t² + c₁

when t =0, x = 0

c₁ = 0

x = 0.6 t³ + 2.8 t²

when t = 1.6

x = .6 x 1.6³ + 2.8 x 1.6²

= 2.4576 + 7.168

= 9.6256

9.6 m

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3 years ago

A box is pushed 40 m by a mover. The amount of work done was 2,240 j. How much force was exerted on the box

Georgia [21]

The force exerted on the box is 56 N

Explanation:

The work done by a force on an object is given by

$W=Fd cos \theta$

where

F is the magnitude of the force

d is the displacement of the object

$\theta$ is the angle between the direction of the force and of the displacement

For the box in this problem, we have:

W = 2240 J is the work done

d = 40 m is the displacement of the box

Assuming that the force is parallel to the displacement, $\theta=0$

Solving the equation for F, we find the force exerted on the box:

$F=\frac{W}{d cos \theta}=\frac{2240}{(40)(cos 0)}=56 N$

Learn more about work:

brainly.com/question/6763771

brainly.com/question/6443626

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3 0

3 years ago