Answer:
1) Potassium's number of protons is 19
Symbol is K
Mass number is 39.1 u
2) Number 79 on periodic table is Gold
Symbol is Au,
Mass number is 196.97
3) Metals and non-metals
4) Gases
Iodine
Bromine
Fluorine, chlorine
Explanation:
The modern periodic table is the arrangement of atoms in an increasing atomic number.
The Russian chemist, Dmitri Mendeleev arraigned the elements as they appear in the modern periodic table.
It has 18 groups and 7 periods.
These groups belong to the specific classification of the elements.
The periods referred to as the horizontal rows on the periodic table have given much importance than the vertical columns for the actinides and lanthanides.
It is easy to identify the characteristics of the elements present in the modern periodic table.
Answer:
E) True. The girl has a larger tangential acceleration than the boy.
Explanation:
In this exercise they do not ask us to say which statement is correct, for this we propose the solution to the problem.
Angular and linear quantities are related
v = w r
a = α r
the boy's radius is r₁ = 1.2m the girl's radius is r₂ = 1.8m
as the merry-go-round rotates at a constant angular velocity this is the same for both, but the tangential velocity is different
v₁ = w 1,2 (boy)
v₂ = w 1.8 (girl)
whereby
v₂> v₁
reviewing the claims we have
a₁ = α 1,2
a₂ = α 1.8
a₂> a₁
A) False. Tangential velocity is different from zero
B) False angular acceleration is the same for both
C) False. It is the opposite, according to the previous analysis
D) False. Angular acceleration is equal
E) True. You agree with the analysis above,
Initial velocity u = 40
Angle at launch = 55 degrees
At maximum height v = 0, velocity equation v^2 = u^2 - 2gh,
0 = (40 x sin55)^2 - 2 x 9.81 x h => (40 x 0.819)^2 = 19.62h => h = 32.76^2 /
19.62
Maximum height = 54.7 m
We have v = u - gt => 0 = (40 x sin55) - 9.81 x t => t = 32.76 / 9.81 => t =
3.34 s
Time taken to hit the ground is 2t = 2 x 3.34 = 6.68 s
Distance from castle to trebuchet = utcos55 = 40 x 6.68 x 0.573 = 153.1 m
Answer:
I will answer in English.
Here we will use the relation
Velocity*time = distance
So:
a) velocity = 3m/s
time = 2s
Distance = 3m/s*2s = 6m
b) velocity = 2m/s
time = 3.5s
Distance = 2m/s*3.5s = 7m
c) velocity = 10m/s
time = 0.5s
Distance = 10m/s*0.5s = 5m
d) velocity = 4m/s
time = 2.5s
Distance = 4m/s*2.5s = 9m
e) velocity = 1.5m/s
time = 5s
Distance = 1.5m/s*5s = 7.5m
Answer:
The Moon does not fall towards Earth right now because Earth rotates itself. The energy from the Earth's own rotation around its axis is gradually tranferred into energy of the Moon's orbital motion. That's why the Earth's rotating speed decreases but the distance to the Moon increases.
