The body moves in the positive direction of the X-axis at a speed of 3 m / s.

The body moves in the positive direction of the X-axis at a speed of 3 m / s. At the initial moment of time, the X-coordinate of the body is 5 m. Determine the X-coordinate of the body 4 s after the start of time.

Since the body moves in the direction of the OX axis, its projection is positive, therefore, because x0 = 5, then the coordinate increases. Since the body moves in a straight line:
x = x0 + v * t = 5 + 3 * 4 = 17m
Answer: x = 17m