Reliable measurements of force (1 Viewer)

[cookiez69]

Hey guys,

So I have a physics assignment and part of it is me required to perform my own experiment.

Basically, what I planned to do was drop an egg from different heights and see how as height increased the force would also increase. My way of measuring the force was to observe how the egg cracked, but I realised that it's not exactly the most reliable method of showing the increasing force. I don't think I can say in my results that the egg dropped at 20cm was more cracked than the egg dropped at 5cm.

I was wondering if you guys had any better methods of measuring the force of any falling object.

Oh and one more thing. Given the formula 'f=ma', and assuming that the mass of the falling object is the same and that the acceleration due to gravity is 9.8ms^2, why is it that height causes the force to increase when the mass and acceleration are constant?

 

[someth1ng]

I think you're looking for F=dp/dt

That is, the force on an object is equal to its change in momentum.

 

[Parvee]

why is it that height causes the force to increase when the mass and acceleration are constant?

As height increases so does the objects potential energy (U=mgh) and as it falls this is converted to kinetic energy (E=0.5mv^2)

 

[Fizzy_Cyst]

I think you're looking for F=dp/dt

That is, the force on an object is equal to its change in momentum.

^^ this

F = ma is still relevant, however, the 'a' would not be the acceleration due to gravity (that would be the force acting on the egg whilst it is falling), the 'a' would be the acceleration of the egg when it collides with whatever you are dropping it on. This would depend on the velocity at which it strikes the ground (can calculate this from Parv's LOCOE eqn above) and the period over which this contact occurs (have no idea how you could even TRY to measure that, unless you have access to a high speed camera!), perhaps you could assume (incorrectly) that it is constant, this would still show a greater acceleration experienced by the egg as it hits the ground (and hence, greater force)

 

[cookiez69]

^^ this

F = ma is still relevant, however, the 'a' would not be the acceleration due to gravity (that would be the force acting on the egg whilst it is falling), the 'a' would be the acceleration of the egg when it collides with whatever you are dropping it on. This would depend on the velocity at which it strikes the ground (can calculate this from Parv's LOCOE eqn above) and the period over which this contact occurs (have no idea how you could even TRY to measure that, unless you have access to a high speed camera!), perhaps you could assume (incorrectly) that it is constant, this would still show a greater acceleration experienced by the egg as it hits the ground (and hence, greater force)

Ohh thanks so much! Makes much more sense now ^^