The answer is B. magnesium I am pretty sure
D) The speed of a wave slows as it travels at different speed in different media.
Question 18: a
question 19: b
question 20: c
Answer:
Characteristic numbers are dimensionless numbers used in fluid dynamics to describe a character of the flow. To compare a real situation with a small-scale model it is necessary to keep the important characteristic numbers the same. Names of these numbers were standardized in ISO 31, part 12.
Explanation:
In physical science, there are two types of quantity: scalar and vector. While scalar quantities only include the magnitude, vector quantities include both the magnitude and the direction. Displacement is an example of vector quantities. Therefore, it includes magnitude and direction.