Force of 1967 Mustang Impacting Human at 40mph

  • Thread starter jess82
  • Start date
  • Tags
    Physics
In summary: So you we're on the right track with the FΔt=mv formula, it's just that you want to use the change in velocity in the time of collision. Also be sure to convert you're units to mks. In summary, based on the given information and assuming certain simplifications, it is difficult to determine the actual force received in the collision between a 1967 Mustang traveling at 40 mph and a human weighing 179 lbs running at a speed of 3-5 mph. Factors such as the unknown surface area of contact and the different distances over which different parts of the body were accelerated make it challenging to accurately calculate the force. However, using the equations for momentum and force, a rough estimate can
  • #1
jess82
1
0
just a question the mass of a 1967 mustang traveling at 40 mph hitting a human (me) in 1980 my weight 179 lbs traveling across the front of the mustang at full run, maybe 3 to 5 mph. what would be the actuall force be in pounds that i recieved? and i am familiar with f=ma but i can't establish the mass. plus the motion involved. both objects came together at 90 degree angle. i am fine 3 days later walking and talking, but did do a lot of damage to the car. and there was no braking. so a full 40 mph impact. i am lucky just would like to know the forces involved. thanks. jess.
 
Physics news on Phys.org
  • #2
I don't think that it can be determined unless you had been wearing extensive instrumentation when it happened. My primary argument in favour of that is the fact that your surface area that made contact is unknown. It's easy enough to calculate how much energy the car could have imparted to you, but that won't be a measure of how much it did impart. Getting clipped off at the knees and then being cammed up the windshield and over the roof is not the same as taking a full torso impact from a bumper.
 
  • #3
jess82 said:
i am fine 3 days later walking and talking, but did do a lot of damage to the car.

lol what are you made of iron or something? your story doesn't seem believable.
 
  • #4
physwizard said:
lol what are you made of iron or something? your story doesn't seem believable.

That's sort of what I was getting at with the contact point argument. A '67 Stang doesn't have a lot of frontal area, so I'd expect the forces to be concentrated around thigh-level. At 40mph, that's going to break things. This whole bit about a 90° impact is puzzling, though. The only way that I can think of that happening is if he ran into the side of the car. :confused:
 
  • #5
You could estimate the acceleration (g force) if you knew the distance over which your body was accelerated. That distance is likely to be quite short unless you were wearing a huge inflatable suit.

Problem is different parts of your body were accelerated over different distances. If your hips were hit they might have accelerated to 40mph over a distance of an inch but your head and sholders probably stayed put and your body folded until it hit the windscreen or the hood. So the distance over which that part accelerated was probably more like a few feet?

How about we assume you went from 0 to 40mph in two feet and do the sums... Excuse me while I switch to metric...

Initial velocity U = 0
Final Velocity V = 40mph = 18m/s
Distance s = 2 feet = 0.6m

Simplified standard equation of motion..

V2 = U2 + 2as
or
a = V2[/SUPB]/2s

= 182/2*0.6
= 270 m/s2

if 1g is 10 m/s2 then you might have experienced 27g during the impact. Parts of you body were probably subject to considerably more. Imagine if you had been bending down to tie your laces at the time and so your whole body had be hit at once or had been accelerated over say half that distance. Half the distance = double the g force.

I believe I read a NASA paper that said 30-50g is survivable but there is a very real risk of serious injury. There are stats available for the survival rates at 30mph and 40mph. You were very lucky. I think only 1% of pedestrians survive a 40mph impact.
 
  • #6
You could apply f = ma to that if you want.
 
  • #7
jess82 said:
...travelling across the front of the mustang at full run, maybe 3 to 5 mph...

3 mph is walking speed, 5 mph is a lazy jog. A flat out run (for me anyway) is 10-12 mph. At least that's what my GPS tells me.
 
  • #8
You would use Momentum. FΔt=mv. Where t is the time you were in contact with the car mass is YOUR mass and v is your veloctiy. Doing this we could get a rough estimate by making some assumptions and simplifications, and we wouldn't care about the motion or mass of the car, just the result of collision. To simplify matters just assume nothing on the car gave and you we're basically just sent flying at some angle from the car at some velocity.

You get hit and and go flying from the car at a velocity v1 at an angle θ. So you're new motion can be described as x and y components. Vy=v1sin Vx=v1cosθ. You're force in y would be given as, ##F_{y}={\frac{m(v_{yf}-v_{yi})}{Δt}}##The force in x would be given by, ##F_{x}={\frac{m(v_{xf}-v_{xi})}{Δt}}## I would call the direction of your initial motion y and the car's motion x. So you're initial y velocity was 5mph or 2.2m/s. and you're initial x velocity was 0.

Once you find the x and y components of the force exerted on you by the car you can find the magnitude of that force with this ##F={\sqrt{F_x^2+F_y^2}}## and the direction would be given by ##arctan({\frac{F_y}{F_x}})##

So I won't venture to guess how your body rebounded off the car, but you can plug in your estimates into those equations I've layed out and can get a very rough estimate of the kind of force involved. Just be sure to have you're units correct. I'd recommend converting to metric and then you'll get Newtons and just convert that to pounds.

Also, you we're far off when you said F=ma, because that is where the first formula I gave comes from. ##a={\frac{Δv}{Δt}}##→##F=m{\frac{Δv}{Δt}}##→##FΔt=mΔv##
 

1. What is the force of a 1967 Mustang impacting a human at 40mph?

The force of a 1967 Mustang impacting a human at 40mph would depend on various factors such as the weight and speed of the car, as well as the weight and size of the human. However, on average, it could range from 5,000-10,000 Newtons.

2. How does the force of impact affect the human body?

The force of impact can result in serious injuries or even death, depending on the severity and location of the impact. It can cause internal damage to organs and tissues, as well as external injuries such as bruises, cuts, and broken bones.

3. Can a person survive being hit by a 1967 Mustang at 40mph?

Surviving being hit by a 1967 Mustang at 40mph is highly unlikely. The force of impact is equivalent to being hit by a small elephant and can cause fatal injuries. However, survival may be possible with immediate medical attention and luck.

4. How can the force of impact be reduced in a car accident?

The force of impact can be reduced by implementing safety features in cars, such as airbags, seatbelts, and crumple zones. It is also important to follow traffic laws and drive at safe speeds to minimize the force of impact in case of an accident.

5. Are there any long-term effects of being hit by a car at 40mph?

Being hit by a car at 40mph can result in long-term physical and psychological effects. These may include chronic pain, mobility issues, and post-traumatic stress disorder. It is important to seek medical and psychological support after such an incident.

Similar threads

  • Other Physics Topics
Replies
1
Views
2K
Replies
19
Views
1K
Replies
7
Views
2K
Replies
2
Views
190
Replies
13
Views
1K
  • Other Physics Topics
Replies
4
Views
4K
  • General Engineering
Replies
3
Views
1K
Replies
1
Views
555
Replies
1
Views
1K
Back
Top