The following answers apply;
- Changes in magnetic properties of rock
- Decrease in well water levels
- Increases in radon gas in groundwater
- Foreshocks
These other choices may be good indicators of an imminent volcanic eruption;
Movement of magma
Increase in sulfur dioxide and carbon dioxide ground emissions
Answer:
1. 20.54m/s
2. 1.52s
Explanation:
QUESTION 1:
The speed the stone impact the ground is the final speed/velocity, which can be calculated using the formula:
v² = u² + 2as
Where;
v = final velocity (m/s)
u = initial velocity (m/s)
a = acceleration due to gravity (m/s²)
s = distance (m)
From the provided information, u = 5.65m/s, v = ?, s = 19.9m, a = 9.8m/s²
v² = 5.65² + 2 (9.8 × 19.9)
v² = 31.9225 + 2 (195.02)
v² = 31.9225 + 390.04
v² = 421.9625
v = √421.9625
v = 20.5417
v = 20.54m/s
QUESTION 2:
Using v = u + at
Where v = final velocity (m/s) = 20.54m/s
t = time (s)
u = initial velocity (m/s) = 5.65m/s
a = acceleration due to gravity (m/s²)
v = u + at
20.54 = 5.65 + 9.8t
20.54 - 5.65 = 9.8t
14.89 = 9.8t
t = 14.89/9.8
t = 1.519
t = 1.52s
Answer:
It is 52° below the celestial equator.
Explanation:
The declination is the angle in degrees measured north (+) or south (-) of the an imaginary line called the celestial equator.
The celestial equator is a projection of the earth's equator on the celestial sphere. imaginary
The star named Canopus has a declination of approximately –52°.
Since the angle is negative, this shows that it is south or below the celestial equator and at 52° south of the celestial equator.
Thus, the star named Caponus is 52° below the celestial equator.
Answer:
the pressure at the depth is 1.08 ×
Pa
Explanation:
The pressure at the depth is given by,
P = h
g
Where, P = pressure at the depth
h = depth of the Pacific Ocean in the Mariana Trench = 36,198 ft = 11033.15 meter
= density of water = 1000 
g = acceleration due to gravity ≈ 9.8 
P = 11033.15 × 9.8 × 1000
P = 1.08 ×
Pa
Thus, the pressure at the depth is 1.08 ×
Pa
Yea it’s called the Saffir-Simpson Hurricane scale, made in 1960s and further developed in 1970s