Question

If 20 waves of water pass you in 5.0 s and the waves are 2.0 m long, how fast are they moving?

1.0 m/s , 2.0 m/s , 4.0 m/s , or 5.0 m/s ?

Answer 1

is 2.0 meters the wave length ?

Answer 2

i think so :)

Answer 3

ohh so our solution is 2.0 m/s?

Answer 4

I'm pondering...

Answer 5

ok!

Answer 6

if 20 waves pass in 5 seconds, the one wave pass in 5/20=0.25 seconds

Answer 7

so I see one wave length every 0.25 seconds, and the requested speed is:
2/0.25=8

Answer 8

what is wrong in my reasoning?

Answer 9

ohh okay! ermm i am not sure... :/ the solution is 8 though right? :/

Answer 10

i am not sure why that is not a choice? :/

Answer 11

because your reasoning makes sense :/

Answer 12

yes!

Answer 13

okay! thank you!! :)

Answer 14

I'm sorry!

Answer 15

haha it is okay! thank you:)

Answer 16

please try to ask to another tutor

Answer 17

okie:)

Answer 18

thankyou!!

Answer 19

please wait I call for another tutor

Answer 20

okie! :)

Answer 21

@Australopithecus please help!

Answer 22

@Hero please help

Answer 23

@amistre64 please help

Answer 24

@sammixboo please help

Answer 25

@Jaynator495 please help

Answer 26

@Nnesha @ParthKohli please help

Answer 27

\[v = f \times \lambda\]

Answer 28

v - velocity of the wave.
f - frequency of the wave (number of waves passing in 1 second).
\(\lambda\) - wavelength, or length of a wave.

Answer 29

so f=20/5 = 4 waves per second?
and wavelength is 2.0 m ?

Answer 30

That is correct. The answer is thus \(4 ~s^{-1} \times 2 ~m = 8 ~ms^{-1}\).

Answer 31

ooh okay! hmm i am not sure then :/ i was not given that choice :(

i think maybe a typo? haha :P but yes, thank you both very much!!:)

Answer 32

thanks! @ParthKohli