I have no clue

1. Feb 2, 2005

Lovely

I have searched for this answer all day long.
Why is Vave multiplied by 2 to obtain Vf?

2. Feb 3, 2005

sharans

i feel Vave=(Vf+Vi)/2
since Vi=0,we have the result.

3. Feb 3, 2005

Gokul43201

Staff Emeritus
Going by the definitions, we have, for the average velocity :

$$v_{ave} = \frac{total~distance~traveled}{total~time~taken} = \frac {s}{t}$$

Now just substitute for s, from the equations of motion to get the required result.