D. all of the above
Explanation:
The best answer from the choices is option D all of the above.
Speed is a key component aspect of almost all sport.
What is speed:
Speed is the rate of change of distance with time;
Speed = 
distance is the path taken by a body
time is the duration of interval
In tennis, speed is very essential and critical same as soccer and swimming. In fact, sports with more speed have very good advantage at excelling.
learn more:
Speed brainly.com/question/10435836
#learnwithBrainly
If this were to happen then the particle would be at the node (the point in the middle where the lines meet). Therefore, the particle will not move up or down because you can see the waves interfere destructively so there is no movement at the node.
answer. The particle will remain stationary due to interference.
Explanation:
When water vapor in the air comes into contact with something cool, like the ceiling of a tent, its molecules slow down and get closer together. When that happens, the gaseous water vapor turns back into liquid water droplets. That's condensation!
Answer:
Average speed = 1.2 m/s
Average velocity = 0.4 m/s
Explanation:
Average speed = total distance/total time
Average speed = (40 + 20)/(40 + 10)
Average speed = 60/50
Average speed = 1.2 m/s
Average velocity = displacement/time
Now, she ran 40 m south and ran 20 m back north which is in the direction of where she began the journey.
Thus;
Displacement = 40 - 20 = 20 m
Average velocity = 20/50 = 0.4 m/s
