What is the best way to determine levelness?

A. See if the Acceleration versus Time for both directions are both zero.

B. Plot the Acceleration versus Time for one direction and acceleration should be zero.

C. Plot Position versus Time and compare the linear fit from each direction of travel; slopes should be equal.

D. Plot Position versus Time and compare the linear fit from each direction of travel; slopes should be equal but opposite.

E. Plot Velocity versus Time for both directions; slopes should be equal.

F. See if slope of Velocity versus Time for both directions are equal but opposite.

F. See if the slope of Velocity versus Time for both directions are equal but opposite.

Explanation: Velocity is the rate of change of position. The slope of a distance or position-time graph is velocity. Acceleration is the rate of change of velocity. The slope of a velocity-time graph is acceleration.

A velocity-time graph shows changes in the velocity of a moving object over time. The slope of a velocity-time graph represents an acceleration of the moving object.

So, the value of the slope at a particular time represents the acceleration of the object at that instant.

d) physical means can be used to separate the components of air.