You call out to your friend who is standing at a distance of 350 m.

a) if the temperature of the air is 35 degrees Celsius, find the time when your friend will hear you after you have called her.

b) Find the wavelength of your sound if your frequency is 1.3 khz

You will have to look up the speed of sound in meters/s, somewhere around 350, at 35 C ,call it v

distance = speed * time

(a) t = 350/v

(b) period = T = 1/f
wavelength = speed * period

lambda = v /1300

Where did you get 1300 for part b

that is the frequency 1.3 kHz =1300 Hz

period = 1/frequency

So for part a i get 1.02 seconds would that be correct

That sounds good. I did not look up the speed of sound at that temp.

I divided 350 by 343

It says 343 is the speed of sound but not for 35degrees?

No, you must look it up

I looked it up and cant find it

http://hyperphysics.phy-astr.gsu.edu/hbase/sound/souspe.html

353 m/s