Position vs. Time

Description

An animation of a red car moving to the right, hitting a wall and then moving backward to the left is shown. Also shown is one of four possible graphs depicting the car’s position as a function of time. The middle panel shows a cursor on a position vs. time graph. This graph is initially blank until the user moves the cursor.

Question

Draw a graph of position vs. time for the car.

Instructor Resources

Reference: See Giancoli-PA: 2-8, Giancoli-SE: 2-1.

Answer: The figure shows a crudely sketched answer drawn by dragging the cursor in the middle panel. Since this is a problem designed for inside the classroom instruction, the instructor can use the middle panel in many different ways. Given Animation 1, the instructor can either show the remaining graphs or solicit a volunteer from the class to use the cursor in the middle panel to “draw” the correct position vs. time graph. Once this is completed, the instructor can interact with the class to determine whether the volunteer has drawn the correct curve. Another possible use for the middle panel is to have students draw the velocity vs. time graph when the correct position vs. time graph is shown. This allows students to see an animation and to see the correct graphical representation of that motion.

Script Authors: Mario Belloni and Wolfgang Christian