I need this to be correct and explane why its that answer.

An object 4 cm high is placed 20 cm in front of a convex lens of focal length 12 cm. What is the position and height of the imag

aleksandrvk [35]

It would be 12cm

hope this helps

6 0

3 years ago

Which is an example of a covalent bond?

velikii [3]

The correct answer is definitely C. There are less than 16 valence electrons in 2 chlorine atoms, but they form a stable bond because a covalent bond should involve <span>a pair of electrons between atoms in a molecule. I thing it's pretty clear. Regards!</span>

4 0

3 years ago

Glass has a hardness that is in the middle of the hardness scale. What is the hardness of Glass?

sweet [91]

Answer: 5.5

Explanation:

Let's start by explaining that hardness is a property that materials have related to the opposition or resistance they offer to alterations such as penetration, abrasion, scratching, cutting, and permanent deformations, among others.

In this context, several hardness scales have been developed to catalog the materials (specifically minerals), being the Mohs scale the best known. This scale, proposed by the German geologist Friedrich Mohs in 1825, consists of a ratio of ten minerals numbered in increasing order by hardness, from least to greatest.

This is how the scale starts at 1 with the talc (considered the softest material) and ends at 10 with the diamond as the hardest.

Now, if we are told that the glass is in the middle of the hardness scale that goes from 1 to 10, logically its value will be 5 (volcanic glass). However, according to the scale, the glass is at 5.5.

8 0

3 years ago

Read 2 more answers

When developing an experimental design, which action would improve the

il63 [147K]

When developing an experimental design, the action that would improve the quality of the results is to ensure that it answers a question about cause and effect.

<h3>What is experimental design?</h3>

Experimental design is a concept used to organize, conduct, and interpret results of experiments in an efficient way, making sure that as much useful information as possible is obtained by performing a small number of trials.

Thus, when developing an experimental design, the action that would improve the quality of the results is to ensure that it answers a question about cause and effect.

Learn more about experimental design here: brainly.com/question/17274244

#SPJ1

8 0

1 year ago

At the same moment, one rock is dropped and one is theown downwand with an iniial velocily of 29 us frm op of a building that is

Helen [10]

Answer:

The thrown rock will strike the ground $2.42s$ earlier than the dropped rock.

Explanation:

<u>Known Data</u>

$y_{i}=300m$

$y_{f}=0m$
$v_{iD}=0m/s$
$v_{iT}=-29m/s$ , it is negative as is directed downward

<u>Time of the dropped Rock</u>

We can use $y_{f}=y_{i}+v_{iy}t-\frac{gt^{2}}{2}$ , to find the total time of fall, so $0=300m-\frac{(9.8m/s^{2})t_{D}^{2}}{2}$ , then clearing for $t_{D}$ .

$t_{D}=\sqrt[2]{\frac{300m}{4.9m/s^{2}}} =\sqrt[2]{61.22s^{2}} =7.82s$

<u>Time of the Thrown Rock</u>

We can use $y_{f}=y_{i}+v_{iy}t-\frac{gt^{2}}{2}$ , to find the total time of fall, so $0=300-29t_{T}-\frac{(9.8)t_{T}^{2}}{2}$ , then, $0=-4.9t_{T}^{2}-29t_{T}+300$ , as it is a second-grade polynomial, we find that its positive root is $t_{T}=5.4s$

Finally, we can find how much earlier does the thrown rock strike the ground, so $t_{E}=t_{D}-t_{T}=7.82s-5.4s=2.42s$

6 0

3 years ago