<u>Answer</u>
C.39.2 kPa
<u>Explanation</u>
The pressure in liquids depend on the depth or what we call the liquid column(h), the density of the liquid(σ) and the the acceleration due to gravity(g).
h = 4.00 m
σ = 1000 Kg/m³
g = 9.8m/s²
Pressure Is given by;
P = σgh
= 1000 × 9.8 × 4
= 39200 Pa
=39.2 KPa
Newton's third law of motion states that for any action, there is equal and opposite force. For a person standing on a floor, the action force is the weight and thus the floor must exert an opposite and equal reaction force equivalent in magnitude to the weight of the person.
In this regard, statement 3. is correct.
Density = (mass) / (volume), no matter how large or small the sample is.
We can't calculate the density, because you left out the number for the volume.
Also, you didn't tell us the unit for the mass of 180.
a). If the mass is 180 grams, then the density is
(180 gm) / (volume) .
b). No matter how many pieces you crush it into, and
no matter how large or small a piece is, its density is
the same. (I just wish we knew what the density really is.)
c). A piece may have 80 grams of mass. It doesn't "weigh" 80 grams.
Since the density of the whole rock is (180 gm) / (volume),
the density of any piece of it is (180 gm) / (volume).
Multiply each side by (volume): (Density) x (volume) = 180 gm
Divide each side by (density): Volume = (180 gm) / (density)
We can't calculate the volume of an 80-gm piece, because
we don't know the density. (That's because you left the volume
out of the question.)
