A horizontal line on a speed/time graph means a constant speed.
It is Real,Virtual,The Same Size, Inverted
Answer:
Positive ions, or cations.
Answer: Air
Explanation: Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. Air and hydrogen have nearly the same elastic properties, but the density of hydrogen is less than that of air. Sound thus travels faster (about 4 times as fast) in hydrogen than in air.
Answer:
819.78 m
Explanation:
<u>Given:</u>
- OA = range of initial position of the airplane from the point of observation = 375 m
- OB = range of the final position of the airplane from the point of observation = 797 m
= angle of the initial position vector from the observation point = 
= angle of the final position vector from the observation point = 
= displacement vector from initial position to the final position
A diagram has been attached with the solution in order to clearly show the position of the plane.

Displacement vector of the airplane will be the shortest line joining the initial position of the airplane to the final position of the airplane which is given by:

The magnitude of the displacement vector = 
Hence, the magnitude of the displacement of the plane is 819.67 m during the period of observation.