Find Time for TBI Injury Risk: Hardwood vs Carpeted Floors

  • Thread starter Thread starter Snaveekim
  • Start date Start date
  • Tags Tags
    Time
Click For Summary

Homework Help Overview

The discussion revolves around calculating the magnitude and duration of deceleration for a child rolling off a bed onto different types of flooring, specifically hardwood and carpeted floors. The context involves understanding the conditions under which traumatic brain injuries may occur due to impacts resulting from falls.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the need to first determine the speed of the child's head at the moment of impact, suggesting the use of kinematic equations that do not require time to be known initially. There is also a focus on calculating acceleration and impact duration afterward.

Discussion Status

Some participants have provided guidance on the steps to take, emphasizing the importance of understanding kinematic equations. There is an ongoing exploration of the problem, with participants expressing a desire for further clarification on the equations involved.

Contextual Notes

The original poster expresses uncertainty about finding time and indicates a desire to learn rather than receive direct answers. There is a mention of the complexity of the fall potentially affecting head velocity, which remains an open consideration in the discussion.

Snaveekim
Messages
2
Reaction score
0

Homework Statement


Traumatic brain injury such as concussion results when the head undergoes a very large acceleration. Generally, and acceleration less then 800 m/s^2 lasting for any length of time will not cause injury, whereas an acceleration greater then 1000 m/s^2 lasting for a least 1 millisecond will cause injury. suppose a small child rolls off a bed that is 0.40 m above the floor. if the floor is hardwood, the child's head is brought to rest in approximately 2.0 mm. if the floor is carpeted, this stopping distance is increased to about 1.0 cm. Calculate the magnitude and duration of the deceleration in both cases, to determine the risk of injury. Assume the child remains horizontal during the fall to the floor. Note that a more complicated fall cound result in a head velocity greater or less than the speed you calculate


Homework Equations


Vf=at+Vo


The Attempt at a Solution


a=-9.8 m/s^2
t=?
Vo=0
Xo=0
Xf=.4m

The only problem I have with this question is, finding time, and without time I couldn't really start. so any tips on how to start this? I don't want the answer really this is my first year of physics and I would love to understand this.
So if someone could teach me how to solve for time that would be great!
 
Physics news on Phys.org
You first need to find the speed of the child's head at the instant it hits the floor. You can do this without knowing the time of the fall, by using another kinematic equation. then move on to the 2nd step to calculate the acceleration during , and duration of , the impact.

Welcome to PF!
 
PhanthomJay said:
You first need to find the speed of the child's head at the instant it hits the floor. You can do this without knowing the time of the fall, by using another kinematic equation. then move on to the 2nd step to calculate the acceleration during , and duration of , the impact.

Welcome to PF!

I don't know many Equations so would you mind showing me the way?

and thank you and congrats on 4,444 posts :)
 

Similar threads

Calculating Magnitude and Duration of Deceleration in Fall from Bed
  • · Replies 1 ·
Replies
1
Views
2K
Physics acceleration problem: falling to ground
  • · Replies 14 ·
Replies
14
Views
11K
Calculating deceleration .need quick help, please
  • · Replies 1 ·
Replies
1
Views
3K
Head Fall Acceleration Question
  • · Replies 3 ·
Replies
3
Views
3K
Hip Fracture Falls: Reduce Speed with Elastic Hip Pads
  • · Replies 7 ·
Replies
7
Views
16K
Quick question on experimental errors
  • · Replies 4 ·
Replies
4
Views
7K
What is the maximum upward acceleration of the ball?
  • · Replies 2 ·
Replies
2
Views
5K
Finding Time and Distance in a Lion-Monkey Chase
  • · Replies 2 ·
Replies
2
Views
4K
How Long to Accelerate for Desired Time?
  • · Replies 62 ·
3
Replies
62
Views
7K
What Are Some Challenging Physics Mechanics Questions?
  • · Replies 3 ·
Replies
3
Views
8K