Police-Thief Chase

PREDICTION CHALLENGE: POLICE-THIEF CHASE

SCENARIO

A thief robs a bank and gets into his car. He flees the scene at constant speed but above the speed limit on the zone.

A policeman parked near the bank is enjoying a bagel and coffee. When he sees the speeding car, he drops the coffee and starts chasing the thief!

TASK

Recreate the incident using a battery operated car for the thief and a fan cart for the police.

PREDICTION CHALLENGE

If the police leaves a few seconds after the thief, where and when does he catch the thief?

Your team will produce a video and use LoggerPro to create a position versus time graph of the incident.

LAB JOURNAL

The following items should be included in your Lab Journal

Sketch:

A sketch of your lab setup. Identify each of the elements: which object represents the thief, the police...

Motion Representations:

For each object (thief and police), include:

    • Verbal Description of Motion
    • Motion Diagram (velocity and acceleration). Use your ruler and clearly label the vectors
    • Type of Graph
    • Describe the relationship between variables and the type of motion that each object has

Cut and Paste your graph in your Lab Journal.

Graph:

    • Draw the appropriate curves on your graphs
    • Calculate the slope of the line for the thief. What does this represent? What are the units?
    • Draw a tangent to a point on the police's graph exactly where he meets the thief's car and calculate the slope. What does this represent? What are the units?

Data:

Thief

Initial position, time and velocity

Police

Initial position and time

Police-Thief meeting point

Position

Time

Velocity of thief

Velocity of police

(Thanks to Dolores Gende for this activity)