A railway-line testing-team checking a continuous rail of length 250 m. One tester strikes one end of the rail with a hammer. The other tester hears the sound transmitted through the air and transmitted through the rail. He hears the two sounds at different times. [The speed of sound in steel is 5000 m/s and in air is 330m/s.] b) As the sound wave passes from the end of the beam steel into air.
State the effect of that on

i) the speed of the sound. ………………………………………………………………..