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

AI Thread Summary
To calculate the force of impact when a ball hits the ground, knowing the mass and speed just before impact is essential. The formula used is Force = (mass of the ball) x (speed of the ball) / (time of contact with the ground). However, determining the time of contact is challenging and can vary based on factors like the coefficient of restitution and the deformation of both the ball and the ground. Without precise values for these variables, any calculation will only yield a rough estimate. Accurate impact force calculations require careful consideration of multiple factors influencing the impact event.
Mike123mike
Messages
2
Reaction score
0
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.
 
Physics news on Phys.org
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.
 
I have recently been really interested in the derivation of Hamiltons Principle. On my research I found that with the term ##m \cdot \frac{d}{dt} (\frac{dr}{dt} \cdot \delta r) = 0## (1) one may derivate ##\delta \int (T - V) dt = 0## (2). The derivation itself I understood quiet good, but what I don't understand is where the equation (1) came from, because in my research it was just given and not derived from anywhere. Does anybody know where (1) comes from or why from it the...
Back
Top