The amount of freeze protection in a coolant can be checked by using
a. litmus paper.
b. ph tags.
c. a hydrometer.
d. a color chart.

The correct answer for this question is letter C. A hydrometer is used to measure the specific gravity of liquids. Antifreeze or freeze protection is added to make the freezing point lower. Litmus paper, pH tags and color charts are used to determine the acidity of a substance.

Answer form flower;

You need to be more specific.  i really don't know what a "motion map" is.you can draw a graph of an object's position, distance, displacement, speed,velocity, or acceleration versus time, or you can draw a graph of the object's x-position versus its y-position and not give any information about time at all.if the graph presents position or displacement against time,  then constant velocity is a straight line . . i.e. a line that has  constant slope.if the graph shows speed against time, then constant velocityis a horizontal piece of line.if the graph shows acceleration against time, then constant  velocity is a piece of line that lies on the x-axis . . it's value is zero.