Take the upward and to-the-right directions to be positive (so down and to-the-left are negative).
The vertical forces acting on the object cancel, 6 N - 6 N = 0.
The horizontal forces exert a net force of 20 N - 3 N = 17 N. This net force is positive, so it points to the right. So the answer is A.
Answer:
The particles have just enough energy to move past each other.
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;
B. Increased levels of carbon dioxide, a greenhouse gas, leads to increased phytoplankton growth.
Explanation;
-A combination of warm water, high nutrient levels, and adequate sunlight may cause a harmful algae bloom. These blooms may damage aquatic ecosystems by blocking sunlight and depleting oxygen that other organisms need to survive.
-Algae blooms have been increasing globally, and climate change may be playing a role in the increment. For instance, during the warm summer season or when water is warmer, some harmful types of algae to grow faster than other, more benign varieties.
-Additionally, the warmer surface water also prevents water from mixing vertically, allowing algae to grow thicker and faster.
