Answer:
- a change in color
- the formation of a precipitate
- the formation of bubbles
Explanation:
In a chemical reaction, there is always a rearrangement of atoms within the molecules of reactants to form new products. Such a change is different from changes in the physical form of molecules, e.g. shape.
Thus, according to this criteria, only three options are correct in the given question. A change in color is definitely an indication of chemical reaction because the emission of light before and after cannot be changed unless molecules are rearranged to form a new chemical. Likewise, precipitates form when a reaction takes place between chemically dissolved molecules to form less or not dissolvable compounds. In the end, the configuration of bubbles also indicates that the reaction has taken place because new gases are being released.
On the other hand, change in shape is a physical change because the composition doesn't need to also been changed. An example is the ice formation from water. Same is the case with "change of clear liquid to cloudy" because the addition of non-reactive substances could change the nature of liquid to cloudy however the reaction doesn't need to have taken place.
Answer:
The tension in the left side string = 17.21 N
The tension in the right side string = F = 27.3 N
Explanation:
Given that
F= 27.3 N
M= 1.43 kg ,r= 0.0792 m
Moment of inertia of disk ,I = 0.5 m r²
I = 0.5 x 1.43 x 0.0792² = 0.0044 kg.m²
m= 0.7 kg
Lets take linear acceleration of system is a m/s²
Lets take tension in left side string = T
From Newtons law
T- mg = ma
T- 0.7 x 10 = 0.7 a ----------1
(F - T) r = I α
α = Angular acceleration of disk
a = α r
(F - T) r = I α
(F - T) r² = I a
( 27.3 - T) x 0.0792² = 0.0044 a --------2
Form equation 1 and 2
a= 1.42 T - 10 m/s²
a = 1.42 ( 27.3 - T) m/s²
1.42 T - 10 = 38.9 - 1.42 T
T=17.21 N
The tension in the right side string = F = 27.3 N
It take <u>approximately 29</u><u>.</u><u>5 </u><u>days</u> for moon to do its entire set of phases.
<h3>Explanation</h3>
The Moon is the only natural satellite of the Earth which undergoes three motions, that is :
- Rotating on its own axis
- Evolving around the Earth
- Together with the Earth evolving around the sun as the center of the solar system
With that, the moon has two periods of revolution, namely:
- Sidereal revolution, which is the original revolution of the Moon. This sidereal revolution is really the time it takes the Moon to orbit the Earth. The sidereal revolution of the moon has a time span of <u>27.3 days</u> or more accurate is approximately 27 days, 7.72 hours.
- Synodic revolution, namely the revolution of the Moon as seen from Earth as a series of moon phases (from the new moon phase, to the next new moon phase). The synodic revolution is slower, because the Moon needs to catch up with the Earth rotating in the same direction as the Moon. The synodic revolution of the moon has a time span of 29.5 days or to be more accurate approx 29 days, 12.734 hours.
1. Monophly - all descendants of an ancestral talon are grouped together (i.e. phylogenetic analysis should clearly demonstrate both monophyly and validity as a separate lineage).
2. Reasonable - with respect to evolutionary relevant criteria, i.e ecology morphology, or biogeography; DNA sequences are a consequence rather than a condition of divering evolutionary lineages
