Select the word from the list that best fits the definition used to compare two specific variables a. line graph b. circle graph c. bar graph .

a. line graph

Explanation:   A line graph is formed by joining the points given by the data with straight lines.

A line graph is usually used to show the change of information over a period of time using two variables . This means that the horizontal axis is usually a time scale, for example minutes, days, months or years; and the vertical axis shows the value of the information that varies in time.

when heated, the valance electrons increased their speed and transferred the heat from electron to electron.   i just took the test.

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.