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Really basic Kinematics problem

  • Thread starter Brewer
  • Start date
  • #1
212
0
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?
 

Answers and Replies

  • #2
nicksauce
Science Advisor
Homework Helper
1,272
5
There is no discrepency. You are simply just not justified in assuming a value for the acceleration.
 
  • #3
212
0
Oh ok thats fair enough. Just assumed I could use g. Obviously not then.
 

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