Answer: Option (B) is the correct answer.
Explanation:
Convection is defined as a process in which a fluid (liquid or gas) is heated and the cooler liquid (more dense) settles or sinks at the bottom whereas a hotter material (less dense) will rises to the top.
For example, ice being less dense (cooler material) will float in a lake whereas liquid water being more dense will sink at the bottom.
Thus, we can conclude that situation in which convection currents most likely occur is within the water in a lake as ice forms on the top.
Answer: Kinetic Molecular Theory claims that gas particles are in continuous motion and completely demonstrate elastic collisions. Kinetic Molecular Theory can be used to describe the rules of both Charles and Boyle. A series of gas particles only has an average kinetic energy that is directly proportional to absolute temperature.
Vitamin A may reduce the risk for certain types of cancers. It also increases the activity of immune system cells.
Answer:
7.53 km
Explanation:
We at given;
Speed of runner; v_r = 8.5 km/hr
Speed of bird; v_y = 17 km/hr
L = 6.4 km
We know that; time = distance/speed.
We are told that the bird starts from 6.4 km from the start and that it flies back to meet the runner after it reaches the finish line. If the total distance back to the runner is x, it means bird distance is 6.4 + (6.4 - x) = 12.8 - x
Thus;
Time of bird(t_y) = (12.8 - x)/17
Thus,
Time of runner(t_r) = x/8.5 hr
To find x, we have to equate the times of the runner and the bird.
Thus;
x/8.5 = (12.8 - x)/17
Multiply both sides by 17 to get;
2x = 12.8 - x
2x + x = 12.8
3x = 12.8
x = 12.8/3
x = 4.27 km
Thus, cumulative distance traveled by bird is; 12.8 - 4.27 = 7.53 km
