Which of the following statements is an accurate description of vibrations?

a. neither ultrasonic nor infrasonic vibrations can be heard by humans.

b. the frequency of infrasonic vibrations is much too high to be heard by humans.

c. ultrasonic vibrations have a frequency lower than the range for normal hearing.

d. infrasonic vibrations are used in sonar equipment as well as to detect flaws in steel castings.

dang that balls went far

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min