Hi,
I need some help on this problems, please

1) A stretched string oscillates with frequency 30 c/sec when produce the 1st. harmony, if its length is 60 cm.and its mass per unit length is 0.5 gm/cm .
Determine:
a) the velocity of the transeverse wave.
b) the tension in the string.

2) A body executing simple.harmonic.motion. at what displacement is the speed C equal to one.half the max velocity ?

3) If a pendulum has a length "L" and a periodic time "T", what will be the periodic time "T" when:
a) "L" is doubled.
b) "L" is halved.

4) What is the periodic time of a 0.5m pendulum on the moon ( g(moon)= 1/6g(earth) )

5) A simple harmonic oscillator has a spring constant of 5N/m if the amplitude of the motion is 15cm , find the total energy of the oscillator.