Not sure the precise concept of "normal observation", but I assume that is observed by "eyes".
Eye observation is basically macroscopic, but when you use a mark, which can be regarded as a point of mass, then it goes to microscopic.
Mark is a reference point which you can compare the relative position change, but with your eyes, first you cannot notice microscopic changes, second the eyes cannot precisely set a stable reference point.
Answer:
Explanation:
Given that, .
Pressure around scuba is
P = 10^5 Pa
1 Pa = 1 N/m²
Then
P = 10^5 N/m²
Descending height
h = 10m
Change in force per unit square centimetre
We know that,
Pressure = Force / Area
Then,
Force / Area is the required question we are finding
Then,
Force / Area = 10^5 N / m²
So, let convert the m² to cm²
100cm = 1m
(100cm)² = (1m)²
10⁴cm² = 1m²
Then,
Force / Area = 10^5 N/m² × 1m² / 10⁴cm²
Force / Area = 10 N/cm²
So, the force per unit square centimeters is 10.
The prefix for oxygen in As2O5 is PENTA.
Penta is used to show that the number of oxygen atoms present in the compound is five. Penta means five, while mono mean one, di means two, tri means three and tetra mans four and so on. The chemical name for the given compound is Arsenic pentoxide.
Answer:
c. length of the wall or column and the rate of placement of the concrete
Explanation:
when designing for wall and column form-works, it is of utmost important to know the length of the wall and the type of concrete placement to be used.
Concrete placement has methods and precaution to be taken when doing the form work
if the concrete placement is manually (hand or funnel) the form work height should not be more than 1 m to enable easy compaction and vibration of concrete in the form.
Also, if the form work length is too long and it is not well reinforced, it tends to burg if the force apply during concrete placement or during vibration is much.
