Asound wave has a frequency of 619 hz in air and a wavelength of 0.51 m. what is the temperature of the air? assume the velocity of sound at 0◦c is 335 m/s.

- 32.18 °C

Speed of the sound is given by the product of frequency and wavelength.

Speed = frequency × wavelength

           = 619 Hz × 0.51 m

           = 315.69 m/s

Speed of sound at 0◦C is 335 m/s.

But; Speed of the sound = 335  + 0.6 T

       315.69 = 335 + 0.6 T

          T = - 32.18 °C

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.