Why Are My Calculations for Particle Velocity So Inconsistent?

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SUMMARY

The discussion centers on the calculation of particle velocity for a 50g particle that drops from rest, covering 1 meter in 12 seconds. The user initially applies the formula v = u + at, assuming acceleration due to gravity (g), resulting in a final velocity of 12g. However, using the formula h = (u + v)t/2 yields a final velocity of 1/6, highlighting a significant discrepancy. The resolution emphasizes that the assumption of constant acceleration due to gravity is unjustified in this scenario, leading to the conclusion that the user must not assume g without proper justification.

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Brewer
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This is doing my head in. It should be really simple, but I just can't work out the reasons why.

I have a particle of 50g that drops from rest. It drops 1m in 12s.

I then have to find the final velocity of the particle after this 12s.

Using v = u + at I get v=12g

Using h = (u+v)t/2 I get v=1/6.

This is clearly quite a large discrepancy, andI can't see why. Can anyone put me out of my misery with this please?
 
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There is no discrepency. You are simply just not justified in assuming a value for the acceleration.
 
Oh ok that's fair enough. Just assumed I could use g. Obviously not then.
 

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