Pulley question! String tensions! Anyone? Help

A wooden block of weight 50 N (mass 5.0 kg) is raised by a rope from the ground through a pulley...

a) If the tension in the rope is 80N, find the acceleration of the wooden block as it is being raised.
b) How much tension in the rope will produce an acceleration of 3 m/s?
c) How much tension produces a steady velocity?

This is my second question about physics. Exams is tomorrow sooooo HELP PLEASE PEOPLE! Oh and slow and steady on the explanation, imma big fail in physics :(

A.
When the block goes upward, then equation in use will be as
T = ma + mg (Substituting all the values)
80 = 5a + 50
5a =30
a = 6m/s^2

B.
Same equation again,
T = ma + mg
T = 5 x 3 + 50
T = 65N

C.
a will be 0 for this.
T = F = 50N

if the pulley is assumed as frictionless nd mass less then

1. apply F=ma upwards
T - F = ma
80N - 50N = 5kg * a
a = 25 m/s^2

2. apply F=ma upwards
T - F = ma
T - 50N = 5kg * 3m/s^2
T = 65N

3. steady velocity means 0 acceleration
a = 0m/s^2
so wen F=ma is applied upwards
T -F = ma
T - 50N = 5kg * 0
T = 50N

Hope this helped You. have fun