42.9°
Step-by-step explanation:
Let's assume that the x-axis is aligned with the incline and the positive direction is up the incline. We can then apply Newton's 2nd law as follows:


Note that the net force is zero because the block is moving with a constant speed when the angle of the incline is set at
Solving for the angle, we get

or

![\;\;\;= \sin^(-1)\left[\frac{34\:\text{N}}{(5.1\:\text{kg})(9.8\:\text{m/s}^2)}\right]](https://img.qammunity.org/2022/formulas/physics/college/89c6vy6nz0zm8no8imh0g9s0tb8mkvne0g.png)
