Answer: 8 meters per second
Step-by-step explanation:
Hi, to answer this, first, we have to divide the time counted by the number of waves, to obtain the time of each wave:
10 /20 = 0.5 seconds per wave
Now, we simply divide the distance given by the time, to obtain the speed rate:
4/0.5 = 8 meters per second
Feel free to ask for more if needed or if you did not understand something.
