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4 years ago

Question 10(Multiple Choice Worth 7 points)

Physics

1 answer:

nataly862011 [7]4 years ago

5 0

Organisms that existed over a limited period

Explanation:

Index fossils are organisms that existed within a limited period in the geologic record.

These fossils are indicator fossils that serves as guide to define the relative ages of rocks in a sequence.

Here are some characteristics of index fossils:

they must have existed over a limited period in their history.
they must be very distinctive with short evolutionary tend.
they must be abundant and highly widespread in the stratigraphic column.

Learn more:

Fossils brainly.com/question/7382392

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You might be interested in

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.

3 0

4 years ago

What is the triboelectric effect?

SSSSS [86.1K]

Answer:

The triboelectric effect is an electrical phenomenon where certain materials become electrically charged after coming into contact with another, different, material. The polarity and strength of the charges produced differ according to material and surface smoothness.

Explanation:

The triboelectric effect causes an electrostatic charge to build up on the fur due to the cat's motions. The electric field of the charges results in a slight attraction of the light plastic pieces to the charged fur. The triboelectric effect is also the cause of static cling in clothes.

I hope this helps, if it doesn't then just message me and ill be more than happy to help :)

6 0

2 years ago

In the game of 9-ball, the pool balls are initially placed in a grouping of which shape?

elixir [45]

It should be a triangle.

8 0

4 years ago

How long will it take a transverse wave to propagate from one end of the string to the other?

Makovka662 [10]

Answer:

Explanation:

The time taken by a transverse wave to propagate from one end to another depends on the number of oscillation made by the wave itself. If the total number of oscillation of the wave is known, the time taken by the wave to propagate through can be determined.

Note that the term "period" is the time taken by a transverse wave to complete one oscillation. So if we know the number of oscillation made in one second by the wave and the total oscillation made, then we can know determine how long it will take a transverse wave to propagate from one end of the string to the other

4 0

3 years ago

Given theta = 7pi/6, find (sec theta, cos theta) ...?

uysha [10]

There is an identity of sin(2pi-x) = -sin(x) and cos(2pi-x) = cos(x). This is what we are going to use.

(7pi/6) = (2pi)-(pi/6)


Therefore:

1) sec(7pi/6) = 1/cos(2pi-(pi/6)) = 1/cos(pi/6) = 2sqrt(3)/3

2) cos(7pi/6) = cos(pi/6) = sqrt(3)/2

I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!

5 0

3 years ago