Question

What is the period of the wave motion for a wave with a frequency of 0.37 kHz?

Answer 1

@vocaloid

Answer 2

period = 1/frequency

if you want SI units, convert KHz to Hz first. your solution will be in seconds.

Answer 3

A sound wave has a frequency of 2004 Hz. What is the distance between crests or compressions of the wave? (Take the speed of sound to be 344 m/s.)

Thank you! I just need formulas relly

Answer 4

wave speed = frequency * wavelength

("distance between crests or compressions" is another way to say wavelength)

Answer 5

Compute the wavelength of an X-ray with a frequency of 8.0 1018 Hz.

Got it!

Answer 6

same formula, but for electromagnetic radiation like x-rays you'll use c = speed of light

Answer 7

Will it be in nm or will I need to convert? I have 3.75 but it says it is wrong

Answer 8

notice how you're in SI units (m/s) which means your answer will be in m

if it asks for nm you need to convert

Answer 9

so the example basically moved the answer into a decimal but I put .375 and that is wrong

Answer 10

c = wavelength * frequency

299,792,458 = (x) * (8.0 * 10^18)

x = 3.74741×10^-11 m = 0.0375 nm

Answer 11

oh I forgot a decimal place okay cool

Answer 12

Picnickers see a lightning flash and hear the resulting thunder 7.60 s later. If the storm is traveling at a rate of 13.0 km/h, how long, in minutes, do the picnickers have before the storm arrives at their location?


I have like 3 more questions but thank you so much for your help

Answer 13

not sure about this one. has something to do with how fast sound travels, and d = rt.

Answer 14

did a quick search of this problem

from the moment the lightening strikes, the sound has 7.60 seconds to travel. sound travels 340 m/s, which means the sound travelled 340 * 7.60 = 2584 m and thus thus the storm is about 2584 meters away.

the storm travels 13.0km/hr, so

d = rt
2584m = (13000m/hr) * t
t = 0.19877 hours = 11.926 minutes

Answer 15

During a thunderstorm, 5.6 s elapses between observing a lightning flash and hearing the resulting thunder. Approximately how far away in kilometers and miles was the lightning flash? (Assume the speed of sound is 344 m/s.)

Is this similar to the previous problem?

Answer 16

I think so, I think you just need to multiply speed of sound by 5.6 s

Answer 17

that's not it it said it was wrong

Answer 18

it says km, did you remember to divide by 1000

Answer 19

it also asks for miles so you also need to do a km --> miles conversion

Answer 20

so I got the 1.926 correct for the kilometers and tried to convert and got it wrong for miles I got 1926 for the miles

Answer 21

keep in mind it says miles, not meters

1 km = 0.6214 miles, so 1.926km = 1.1968 miles

Answer 22

ooooooh right okay

Answer 23

(a) Approximately how long would it take a telephone signal to travel 2800 mi from coast to coast across the United States? (Telephone signals travel at about the speed of light.)

one last question this has a part a and b

Answer 24

simple d = rt problem

2800 miles = 4.506 * 10^6 meters

speed = the speed of light = 299,792,458 m/s

plugging into d = rt ---> 4.506 * 10^6 meters = 299,792,458 m/s * (time)

solve for time. that'll give you time in seconds. convert to whatever unit they ask for.

Answer 25

thank you! all done