Circular motion problem?

Question

A block is hung by a string from the inside roof of a van. When the van goes straight ahead at a speed of 28 m/s, the block hangs vertically down. When the van maintains the same speed around an unbanked curve (r = 150 m), the block swings toward the outside of the curve. Then the string makes an angle with the vertical. Find this angle.

Answer 1

v = 28 m/s; r = 150 m
vert. acceleration ay = g
hor. acceleration ax = v^2/r
angle from vertical = arctan(ax/ay)