Physics: I don't understand how to do a, b and c. Thanks?

(a) magnitude of acceleration, a
= - g cos 35°
= - 9.8 cos 35°
= - ‭8.028 ms⁻¹ (to 3 dec. pl)

(b) Let greatest distance that can be travelled = s
v²-u² = 2as
0²-4² = 2(-‭8.028)s
∴ s = ‭0.997 m (to 3 dec. pl)

(c) Let time for it to reach to the highest position = t
v = u + at
0 = 4 + (- ‭8.028) t
t = ‭0.4983 s
∴ time for it to return to the original position
= 2t = ‭0.9966‬ s = 1.00 s (to 2 dec. pl)

(d) cannot send in 2 photos!
May be, I will give you a displacement-time table (Comment column) later, so that you can plot the graph by yourself. Please wait a bit ...