An electron falls through a distance of 1.5 cm in a uniform electric field of magnitude 2.0 x 104 N C-1. The direction of the field is reversed keeping its magnitude unchanged and a proton falls through the same distance . Compute the time of fall in each case
In my book the following formula is used
t=√2s/a
here s is distance and a is acceleration
it is used when u is zero
u here means initial velocity
so my query is why should we take initial velocity to be zero as nothing such is mentioned in the question
