Answer:
a quantitative observation because it includes numerical data
milligrams
Explanation:
The best unit to measure the mass of a grain of salt is the milligram.
This is about; a thousandth of a gram.
A grain of salt is a very small particle size that can still be visible with the eye.
It has a very low and small mass.
For substances like this, we use the milligram:
1000milligram = 1g
learn more:
Mass brainly.com/question/4736384
#learnwithBrainly
When we jump from the truck and accelerate towards the earth surface, the earth also accelerates towards us but it's acceleration is very negligible.
To find the answer, we need to know about the acceleration of earth due to the gravitational attraction.
<h3>What's the gravitational force between the earth and a person?</h3>
- Gravitational attraction force is GMm/r² between the earth and a person.
- M= mass of the earth
m= mass of the person
r= separation between them.
<h3>What's the acceleration of the earth towards the person when he jumps from a truck?</h3>
- According to Newton's second law, Force = M×acceleration
- Acceleration= Force / M
- Here, Force = GMm/r²,
so acceleration of earth= Gm/r²
- As this acceleration is very small, so we can't notice it.
Thus, we can conclude that the earth also accelerates towards us.
Learn more about the gravitational force here:
brainly.com/question/72250
#SPJ4
