Answer
The magnitude of the force of the stone on the man's hand is $22.6~N$
Work Step by Step
We can find the force $F$ that the man applies on the stone:
$F - mg = ma$
$F = m~(a+g)$
$F = (2.0~kg)(1.5~m/s^2+9.80~m/s^2)$
$F = 22.6~N$
By Newton's third law, the stone applies a force with a magnitude of $22.6~N$ on the man's hand.
