Solving the Speedster Puzzle: Calculating Time to Catch Up

  • Thread starter Thread starter Sar06
  • Start date Start date
  • Tags Tags
    Puzzle Time
Click For Summary

Homework Help Overview

The problem involves a speeding motorist and a police officer in pursuit, focusing on the dynamics of motion and acceleration. The context includes calculating the time it takes for the officer to catch up to the speeder, with considerations of constant speed and acceleration.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • Participants discuss the equations of motion and express uncertainty about incorporating two moving objects into their calculations. There is an exploration of equating distances traveled by both the speeder and the officer.

Discussion Status

Some participants have offered guidance on equating the distance formulas for both objects. There is an acknowledgment of the need to fix units before proceeding with calculations. The discussion reflects a collaborative effort to clarify the approach without reaching a definitive solution.

Contextual Notes

Participants note the challenge of mixed units in the problem and the requirement to consider both the constant speed of the speeder and the accelerating motion of the officer.

Sar06
Messages
4
Reaction score
0
I am stuck on this problem...
A speeding motorist traveling 120 km/h passes a stationary police officer. The officer immediately begins pursuit at a constant acceleration of 10.2 km/h/s (note the mixed units). How much time will it take for the police officer to reach the speeder, assuming that the speeder maintains a constant speed?
 
Physics news on Phys.org
Do you have any equations of motion you are suppose to use?
 
I know 3 equations of motion, but up until now I have only been looking for one variable or working with only one moving object... I'm not quite sure how to incorporate both moving objects into the equations I have. Could someone possibly lead me toward the process for finding the solution? Thanks.
 
You know the distance will be the same so

d = vt
d = 1/2at^2

You can equate those

vt = 1/2at^2

Fix your units and solve.
 
got it!

thank you so much. :smile:
 

Similar threads

How far does the police car travel to catch a speeder traveling at 180 km/hr?
  • · Replies 1 ·
Replies
1
Views
2K
Basic Kinematics problem, why my method is invalid
  • · Replies 2 ·
Replies
2
Views
2K
Calculating the Time for a Car Chase: Kinematics Question
  • · Replies 4 ·
Replies
4
Views
4K
Re: Physics Homework Help, Please
  • · Replies 1 ·
Replies
1
Views
3K
Motorcycle Police Officer Chasing Car
  • · Replies 18 ·
Replies
18
Views
8K
Speeder and Cop Meeting Time Calculation
  • · Replies 11 ·
Replies
11
Views
4K
Interception of a poliece car with speeder from rest
  • · Replies 2 ·
Replies
2
Views
2K
Many failed attempts on this displacement/acceleration/velocity problem.
  • · Replies 1 ·
Replies
1
Views
2K
Constant Acceleration of a motorist
  • · Replies 1 ·
Replies
1
Views
3K
Help Solving Automobile and Train Problems
  • · Replies 25 ·
Replies
25
Views
5K