AP Physics 1 Exam Question - Graphical Analysis of Motion

A car travels along a straight road. The graph below represents the position vs. time graph for the car's motion.

1. Determine the car's velocity at t = 2 seconds.

[A]

Answer:

To determine the car's velocity at a specific time, we need to find the slope of the position vs. time graph at that point. Recall that the slope of a position vs. time graph represents the velocity.

First, we need to identify the position and time values at t = 2 seconds. From the graph, at t = 2 seconds, the car is at a position of approximately 18 meters.

Next, we select two points on the graph that are close to t = 2 seconds, preferably on each side of the point.

Let's choose the points A (1.5, 15) and B (2.5, 22) on either side of t = 2 seconds.

Now, we can calculate the slope using the formula:

Applying this formula, the change in position is (22 - 15) m and the change in time is (2.5 - 1.5) s. Plugging these values into the formula, we get:

Therefore, the velocity of the car at t = 2 seconds is 7 m/s.