Answer:
<h2>20 kg</h2>
Explanation:
The mass of the rock can be found by using the formula

f is the force
a is the acceleration
From the question we have

We have the final answer as
<h3>20 kg</h3>
Hope this helps you
When conducting a search to identify a text's credibility and reliability, you have to check the following characteristics:
- Sources: where the information is obtained and it is supposed to be true. It is said that you need at least three different sources that explain the same information for it to be validated.
- Is the article is current?: articles could change all the time, specially scientific ones because new discoveries can change what was discovered before, so it is important to check if the text you are reading is current or not, and if it is not, you need to check if something has changed during all those years.
<h3>Article's credibility</h3>
In this exercise, you have to present an article and describe the purpose of the source and if the article is current or not.
For example, let's select an article called "How using social media affects teenagers".
The purpose of the sources in this article is to demonstrate how social media affects teenagers using different surveys.
Check more information about sources here brainly.com/question/24708478
Answer:
decreases
Explanation:
The angular frequency of the mass is given by

where, k is the spring constant and m be the mass of the body which is doing oscillations.
if the mass of the body increases, so the value of angular frequency decreases, as the angular frequency is inversely proportional to the square root of the mass of the body.
Answer:

Explanation:
The density of an object is given by

where
m is the mass of the object
V is its volume
In this problem,
m = 42 kg
V = 22 m^3
Substituting into the equation, we find the object's density:

Answer: almost 12 years
Explanation:
Using the radial velocity method, planet hunters can track a sun's spectrum, to determine whether the sun has planets. The spectrum appears first slightly blue-shifted, and then slightly red-shifted. If the shifts are regular, repeating themselves at fixed intervals of days, months, or even years, it is almost certainly caused by a body orbiting the sun, tugging it back and forth over the course of its orbit. Because of the gravitational pull of Jupiter (about 3,000 times the mass of Earth), In which its average distance from the sun is 480 millions miles and takes nearly 12 years to make one revolution.