- #1
gaganspidey
- 20
- 0
Homework Statement
Example 3.13 :
Example 3.1
Homework Equations
v=u+at
S=ut+1/2at2
v2-u2=2aS
The Attempt at a Solution
I know the solution is in front of me, that's ok but I have a confusion regarding negative & positive signs. In both the examples something is moving vertically upwards & in both cases something is released below to the ground, then why in Example 3.13 initial velocity of the stone is taken as u = +12m/s whereas in Example 3.1 u = -2m/s ?
Also in Example 3.13, displacement = -65 m, why ?
Please clear these doubts of mine in as much detail as possible so that I know which sign to use in which case.