College Physics (4th Edition)

The magnitude of the force of the stone on the man's hand is $22.6~N$
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.