#### Answer

At y = 0.5 m, the y-component of the force on the particle is -60 N.
At y = 4 m, the y-component of the force on the particle is 15 N.

#### Work Step by Step

The force $F$ is equal to the negative of the slope of the $U$ versus $y$ graph.
We can find the force on the particle at y = 0.5 m. We can use the points (0 m, 0 J) and (1 m, 60 J) to find the slope;
$F = -\frac{\Delta J}{\Delta y}$
$F = -\frac{60~J - 0~J}{1~m-0 ~m}$
$F = -60~N$
At y = 0.5 m, the y-component of the force on the particle is -60 N.
We can find the force on the particle at y = 4 m. We can use the points (1 m, 60 J) and (5 m, 0 J) to find the slope;
$F = -\frac{\Delta J}{\Delta y}$
$F = -\frac{60~J - 0~J}{1~m-5~m}$
$F = 15~N$
At y = 4 m, the y-component of the force on the particle is 15 N.