1. **State the problem:** An object starts from rest and accelerates at $4$ meters per second squared. We need to find its velocity after $10$ seconds. 2. **Formula used:** The velocity $v$ of an object under constant acceleration $a$ starting from initial velocity $v_0$ after time $t$ is given by: $$v = v_0 + at$$ Since the object starts from rest, $v_0 = 0$. 3. **Apply the values:** $$v = 0 + 4 \times 10$$ 4. **Calculate:** $$v = 40$$ 5. **Interpretation:** After $10$ seconds, the velocity of the object is $40$ (meters per second, but units are not requested).