The discussion centers on calculating the force required to stop a 5kg ball moving at 20m/s instantly, highlighting the unphysical nature of such a scenario. The kinetic energy is calculated using the formula 0.5 * mass * velocity^2, resulting in 1000J. However, attempting to divide this energy by zero distance leads to an undefined force. The conclusion is that stopping an object instantaneously is not feasible, as it would require an infinite force.
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You are not doing it wrong. It is unphysical to ask to stop an object instantly. In the limit as the time goes to zero, the force goes to infinity (using non relativistic formula or even relativistic ones) so it is simply ill-defined.aosome23 said:Homework Statement
Find the force to stop a 5kg ball at 20m/s instantly. Dont take in account resistance.
Homework Equations
kinetic energy = 0.5*mass*velocity^2
Energy = force * distance
force = energy / distance
The Attempt at a Solution
0.5 * 5kg * 20m/s^2 = 1000J
1000J / 0 = ?
As seen it does not work if you want to find the force to counter it exactly...
What am I doing wrong?
Thanks