Answer:
D). 8 kg mass
Explanation:
Acceleration of Falling Objects
Heavier things have a greater gravitational force AND heavier things have a lower acceleration. It turns out that these two effects exactly cancel to make falling objects have the same acceleration regardless of mass.
The greater an object's mass, the greater its gravitational force. The earth has a strong attracting force for objects with smaller mass (including the moon), and the sun has an attracting force on the earth and other planets in our solar system. ... The stronger the pull of gravity on an object, the greater its weight.
After two half-lives or 60 years, 7.5 g of the element will be left.
<u>Explanation:</u>
<u>Half-life:</u>
- In simple words, Half-life can be defined as the amount of time needed for a quantity to fall to half its value as contained at the beginning of the time period.
- In this problem the half-life of the element is thirty years, then after thirty years half of the sample would have decayed and half would be left as it is.
- After thirty years (The first half-life ) 30 /2 = 15 g declines and 15 g remains disappeared.
- And after another sixty years (The two half-lives) 15 /2 = 7.5 g declines and 7.5 g remains disappeared.
- After two half-lives or 60 years, 7.5 g of the element will be left.
c. cell wall, vacuole
Among the choices above, the two features that indicate that a cell is a plant cell is the cell wall and vacuole. The cell wall can only be found in plant cells. It is the rigid cell that surrounds the cell membrane. The vacuole of a plant cell and animal cell are way too different. The vacuole of an animal cell is usually more than one and small, even smaller that that of the plant cell. On the other hand, the vacuole of the plant cell is only one in fact a large one that takes up almost 90 percent of the volume of the cell
Lipids, also known as fats, play multiple roles in the body. Fats are broken down in the digestive tract to form individual fatty acids and cholesterol molecules. <span>Carbohydrates are the preferred source of energy for most of the tissues in the body, including the nervous system and the heart</span>
