Could someone please help me with these problems. I have no clue when it comes to Physics, and any help would be appreciated.
1)A steel wire of mass 0.400kg and length 0.640m supports a 102kg block. The wire is struck exactly at its midpoint causing a small displacement. How long does it take the peak of this displacement to reach the top of the wire?

2)A sound wave of frequency 1000Hz is sent out from a stationary source toward a target approaching at 20m/s. The wave is reflected from the target. What is the frequency of the reflected signal? Take the speed of sound to be 340 m/s.

3)A narrow tube, open at one end-closed at the other, is 40cm long with a radius of 6cm. A tuning fork held over the open-end produces resonance at the fundamental frequency. The sound level at resonance is 30db. The aire temperature is -4 C. Determine the audio power produced at resonance.
Determine the fundamental frequency.