Asound has 13 crests and 15 troughs in 3 seconds. when the second crest is produced the first is 2cm away from the source? calculate

                a. the wavelength

                b. the frequency

                c. the wave speed

The wavelength will be 4 cm, frequency will be 4.66 Hz and wave speed is 18.6 cm/sec

Explanation:

Given:

No. of crest = 13

No. of trough = 15

Time = 3 seconds

Hence, 1 crest or 1 trough =

therefore,

13 C + 15 T =

=

Time given 3 seconds

  =

2 cm distance is travelled is time period

Again wave will travel in 1 T = 4 cm

wave speed v =

=

= 18.6 cm/s

the answer is false. this is because for ice to melt, it requires latent heat of melting. latent heat means heat energy required to change phase without any increase in temperatures. therefore, the ice will take energy from the environment to melt hence atmospheric temperatures will reduce.

b. false

explanation:

suppose a rock in free fall is dropped off a cliff. after falling for 5 seconds, its speed would not be 100 m/s.