- #1
Thoams Jerome
Rolls or brake falls slow down how fast your body hits the ground by well rolling.How does this decrease impacted.
If you roll when you hit the ground you feel less velocity?
In summary, rolling or brake falls can slow down the speed at which your body hits the ground by extending the deceleration time, resulting in a lower peak acceleration. This is because you cannot compress yourself to a point, so you must go sideways. It is similar to the saying, "it's not the fall that kills you, it's the sudden stop at the end." Going sideways or rolling lessens the suddenness of the stop. The equation for this is F = ΔP/Δt, where F represents force, ΔP represents change in momentum, and Δt represents change in time. By increasing the time it takes for the momentum to reach zero, the force acting on the body is reduced. This is why
- #2
mfb
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It is not so much the rolling itself, it is making the deceleration last longer, which means you get a lower peak acceleration. As you can't compress yourself to a point, you have to go sidewards.
- #3
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As an old saying goes: "It's not the fall that kills you, it's the sudden stop at the end." Rolling lessens the "suddenness" of the stop.
- #4
Thoams Jerome
Does anyone have the equation for that?
- #5
Thoams Jerome
How does not being able to comprising yourself to a point, effect you going sidewards?Also if you dropped a object like a box with lightly connected object to hollow space.Like putting a rock that's lighter then the box in the top connected with toilet paper.then dropping it down would the rock go up and take some the energy from the fall with it?mfb said:
- #6
Drakkith
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Thoams Jerome said:
I'm sorry but I can't make any sense out of this.
- #7
berkeman
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I think he's asking about jumping up in a falling elevator to lessen the impact at the bottom (maybe), but I'm not getting the toilet paper angle...Drakkith said:
- #8
Thoams Jerome
Sorry.If you drop a trash can with a light board lightly wedged inside.Will the board jump up when the trash can hits the ground?What are the physics involved.berkeman said:I think he's asking about jumping up in a falling elevator to lessen the impact at the bottom (maybe), but I'm not getting the toilet paper angle...
- #9
pixel
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Thoams Jerome said:
In a fall, you are changing momentum from some initial value to a zero final value. The change in momentum equals the Impulse, which is the integral of the force (in this case the force causing the deceleration) over time. If you can increase the time over which the force acts, less force on average is required. If you don't use a brake or roll fall, the time interval is much smaller so the force is larger to produce the same momentum change.
If you don't know calculus, instead of the integral of force over time just think in terms of the product of the average force and the time interval over which the force acts.
- #10
Drakkith
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Thoams Jerome said:
The board will likely become un-wedged and fall to the bottom of the trashcan upon impact. During the impact, the board experiences a large force from friction that attempts to decelerate it. If, before the board decelerates, it slides enough to break loose completely then it will fall to the bottom.
- #11
mfb
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It doesn't, and no one said that.Thoams Jerome said:
It is advisable to go sidewards. Bending your knees is an example already, and starting to roll is an extension of that approach.
- #12
Kaura
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Thoams Jerome said:
F = ΔP/Δt
Force known in this case as Impulse is equal to a body's change in momentum divided by the change in time. Momentum is the object's mass multiplied by its velocity. From this equation you can see that the longer it takes for the momentum to reach zero the less force acts on a body. In the example of rolling when hitting the ground, doing such a thing gives the person's body more time to change its momentum to reach rest. It is also why landing on a cushion from a high height is far less likely to hurt you compared to landing on concrete. The cushion allows for your body to slow down over a longer period of time.
1. Why do you feel less velocity when you roll after hitting the ground?
When you roll after hitting the ground, your body converts the linear velocity from the fall into rotational velocity. This rotational velocity is then dissipated through the rolling motion, reducing the overall impact and decreasing the feeling of velocity.
2. Is rolling after hitting the ground an effective way to reduce impact?
Yes, rolling after hitting the ground is an effective way to reduce impact. It helps to distribute the force of impact over a larger area of the body, decreasing the amount of force that is absorbed by a single point.
3. What is the difference between rolling and just hitting the ground without rolling?
The main difference between rolling and just hitting the ground without rolling is the way the force of impact is distributed. When rolling, the force is distributed over a larger area, whereas when just hitting the ground, the force is concentrated at a single point, resulting in a higher impact.
4. Are there any risks associated with rolling after hitting the ground?
There are some potential risks associated with rolling after hitting the ground. If not done correctly, rolling can cause strain or injury to certain joints or muscles. It is important to learn proper rolling techniques and to practice them in a safe environment.
5. Can rolling after hitting the ground prevent injuries?
In some cases, rolling after hitting the ground can help prevent injuries. By reducing the overall impact and distributing the force, rolling can decrease the likelihood of severe injuries such as broken bones or sprains. However, it is not a foolproof method and injuries can still occur depending on the height of the fall and the surface of the ground.
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