Murder Mystery Solution using Kinematic Equations

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SUMMARY

The discussion focuses on solving a murder mystery problem using kinematic equations in physics. The key details include a victim, Adam Able, who fell from a height related to the room numbers of four suspects. The kinematic equations utilized are V=Vo+at, X=Xo+1/2(V+Vo)t, and others, with specific values for gravity and initial velocities. The user seeks guidance on correctly applying these equations to determine the height from which Adam fell and identify the murderer based on the suspects' room locations.

PREREQUISITES
  • Understanding of kinematic equations in physics
  • Basic knowledge of projectile motion and gravity
  • Ability to convert units (feet to meters)
  • Familiarity with solving algebraic equations
NEXT STEPS
  • Learn how to apply kinematic equations to real-world scenarios
  • Study the concept of free fall and its implications in physics
  • Explore unit conversion techniques for physics problems
  • Investigate how to analyze motion in both horizontal and vertical directions
USEFUL FOR

This discussion is beneficial for students studying physics, particularly those tackling kinematic problems, as well as educators looking for practical applications of physics concepts in problem-solving scenarios.

kstategirl121
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I'm new to this site, so let me know if I'm doing anything wrong.

Homework Statement


I have attached the original problem in a PDF file. I have to read a murder mystery story and pull information from it to plug into kinematic equations and find out who commited the murder.

Important information that I have pulled out of the story:
--No air resistance
--Each room is has a 14ft high ceiling with 2 feet between each floor.
--Bloodstains are 18ft from the entrance to the building
Victim:
1. Adam Able. 5'11. 160 lbs.

Suspects:
1. Adrianna Myers (Room 356)
2. Steven Caine (Room 852)
3. Mark Johnson (Room 1956)
4. Stanley Michaels (Room 2754)


Homework Equations


Kinematic Equations:
1x. V=Vo+at
2x. X=Xo+1/2(V+Vo)t
3x. X=Xo+volt+1/2at^2
4x. V^2=Vo^2+2a(X-Xo)

1y. Y=Vo+at
2y. Y=Yo+1/2(V+Vo)t
3y. Y=Yo+volt+1/2at^2
4y. V^2=Vo^2+2a(Y-Yo)

Xo & Yo = Initial Position
X & Y = Final Position
Vo = Initial Velocity
V = Final Velocity
A = Acceleration
T = time


The Attempt at a Solution


Knowing that each floor is 16ft total, I use the person's room number to find out high up the are. I know that in the end I need to figure out how high up Adam fell from and compare that to the suspects rooms to know who killed him. Note: I've also converted everything to meters

The first thing I did was solve for time using the x-axis equations.
Xo=0
X= 5.4864 m (18ft where bloodstains were)
Vo = 0 m/s
V = 2 m/s (You'll notice in the attached file that our teacher gives a hint stating that if we were in lab and pushed our partner hard, we'd find that they'd have a speed of 2 m/s)
a = ?
t = Find!
I plugged all of this into Equation 2x and got 5.864 seconds. (I believe this is wrong after going further, I'm just explaining what I did.

The second thing I did was plugged in the time to find out Yo.
Yo = Find!
Y = 0 m
Vo = 0m/s
V = ?
a = -9.81 m/s (Gravity)
t = 5.4864 s
I plugged this into Equation 3y and got 25.24 m. This is seeming way off.

I know this is long. This is a take-home problem for my exam tomorrow. I'm not asking anyone for answers. I just need help going in the right direction. This is my first physics class ever and its turning out to be way harder than I expected and I have no friends takign classes like mine.
 

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For the horizontal motion, Adam's initial velocity will be about 2m/s and there will be no acceleration in the horizontal direction after he's shoved. It looks like your equation 3x would be the better choice, setting a to zero.
 

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