(a) The stone travels a vertical distance <em>y</em> of
<em>y</em> = (12.0 m/s) <em>t</em> + 1/2 <em>g t</em> ²
where <em>g</em> = 9.80 m/s² is the acceleration due to gravity. Note that this equation assume the downward direction to be positive, and that <em>y</em> = 0 corresponds to the height from which the stone is thrown.
So if it reaches the ground in <em>t</em> = 1.54 s, then the height of the building <em>y</em> is
<em>y</em> = (12.0 m/s) (1.54 s) + 1/2 (9.80 m/s²) (1.54 s)² ≈ 30.1 m
(b) The stone's (downward) velocity <em>v</em> at time <em>t </em>is
<em>v</em> = 12.0 m/s + <em>g t</em>
so that after <em>t</em> = 1.54 s, its velocity is
<em>v</em> = 12.0 m/s + (9.80 m/s²) (1.54 s) ≈ 27.1 m/s
(and of course, speed is the magnitude of velocity)
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)
445/100 - 5/4 = 445/100 - 125/100 = 320/100 = 16/5 = 3 1/5.
Answer:
1) D
2) A
Explanation:
1) Each group has the same number of valence electrons, which are the outer electrons.
2) Ionic bonds are between a metal and non - metal, the metal being sodium and the non - metal being chlorine.
