Final answer:
To calculate displacement, you add the initial and subsequent movements taking into consideration their direction. In this question, traveling -50 miles and then +40 miles results in a displacement of -10 miles.
Step-by-step explanation:
The question asks about the concept of displacement, which is a vector quantity describing the change in position of an object. In this case, displacements are measured along a straight line, with negative and positive values indicating direction.
To calculate displacement, you subtract the initial position from the final position. If you travel -50 miles and then +40 miles, your displacement would be the sum of these two values, as displacement takes into account the direction of movement. Here's the calculation:-50 miles (initial movement) + 40 miles (subsequent movement) = -10 miles
Therefore, the displacement is -10 miles. The negative sign indicates that the final position is 10 miles in the opposite direction from the positive direction, which was assumed in the question to be the direction of the initial travel.