How Can You Calculate the Force of Impact Without Knowing All Variables?

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    Force Impact Newtons
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Discussion Overview

The discussion revolves around calculating the force of impact when a ball hits the ground, given limited information such as the mass of the ball and its speed just before impact. Participants explore the necessary variables and formulas involved in determining the force, including considerations of time and other factors affecting the impact.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant proposes using the formula F = m x a but notes the need for distance to calculate acceleration.
  • Another participant suggests that the time the ball is in contact with the ground is also necessary for calculating force, providing a formula that incorporates speed and time.
  • A subsequent participant questions how to determine the contact time, indicating that it may vary with speed.
  • Another participant highlights the complexity of impact calculations, mentioning the coefficient of restitution and deformation of the ball and ground as factors that complicate estimations.

Areas of Agreement / Disagreement

Participants express differing views on the necessary variables for calculating impact force, with no consensus on how to approach the problem or the specific values needed.

Contextual Notes

The discussion lacks specific values for time and distance, and the assumptions regarding the coefficient of restitution and deformation are not fully explored or defined.

Mike123mike
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I have a scenario which is simply a ball hits the ground from above i know the mass of the ball and the speed in mph of the ball just before it hits the ground. No other variables are known, I need to know the force it hits the ground.

What is the best way to calculate it? I had thought F = m x a, but to calculate the acceleration I would need a distance?

Obviously I'm not a physics person and any help would be greatly appreciated.
 
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You also need to know the length of time that the ball is in contact with the ground. The formula for the force exerted is:

Force = (mass of the ball) x (speed of the ball)/(time the ball is in contact with the ground)

In order that the force is measured in Newtons you must use the following units:

mass: kilograms
speed: metres/second
time: seconds
 
Last edited:
Thanks for that dave I don't suppose you can assist in calculating the time it is in contact with the ground as I suppose that time would vary depending on the speed too?
 
Impacts are tricky to just guess at. You'd have to make an educated guesstimate bases on Coefficient of restiution, deformation of ball and ground.

Even then you are only coming up with a very rough average to the impact event.
 

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