Answer:
A) 0.660 g/ml
B) 1.297 ml
C) 0.272 g
Explanation:
Every substance, body or material has mass and volume, however the mass of different substances occupy different volumes. This is where density 
appears as a physical characteristic property of matter that establishes a relationship between the mass 
of a body or substance and the volume 
it occupies:
(1)
Knowing this, let's begin with the answers:
<h2 /><h2>Answer A:</h2>
Here the mass is 
and th volume 
Solving (1) with these values:
(2)
(3)
<h2>Answer B:</h2>
In this case the mass of a sample is 
and its density is 
.
Isolating from (1):
(4)
(5)
(5)
<h2>Answer C:</h2>
In this case the volume of a sample is 
and its density is 
.
Isolating from (1):
(6)
(7)
(8)
Answer:
Explanation:
The unknown charge can not remain in between the charge given because force on the middle charge will act in the same direction due to both the remaining charges.
So the unknown charge is somewhere on negative side of x axis . Its charge will be negative . Let it be - Q and let it be at distance - x on x axis.
force on it due to rest of the charges will be equal and opposite so
k3q Q / x² =k 8q Q / (L+x)²
8x² = 3 (L+x)²
2√2 x = √3 (L+x)
2√2 x - √3 x = √3 L
x(2√2 - √3 ) = √3 L
x = √3 L / (2√2 - √3 )
Let us consider the balancing force on 3q
force on it due to -Q and -8q will be equal
kQ . 3q / x² = k3q 8q / L²
Q = 8q (x² / L²)
so charge required = - 8q (x² / L²)
and its distance from x on negative x side = √3 L / (2√2 - √3 )
<span>1. It must be an object which independently orbits the Sun (this means moons can't be considered planets, since they orbit planets)
2. It must have enough mass that its own gravity pulls it into a spheroidal shape.
3. </span><span>It must be large enough to "dominate" its orbit (i.e. its mass must be much larger than anything else which crosses its orbit).</span>
Both, there are two different types of molecules to distinguish that
