1
Philip Calvert
·2009-08-12 06:01:29
m = - vu
or v= - um
now applying mirror formula....
1/v + 1/u = 1/f
1u - 1um = 1/f
1/u[ 1 -1/m] = 1/f
=> f = umm-1
since f is positive ..... m can be negative only when u is positive
or we can say that sign of 'f' and 'u' is same which implies object is virtual
1
Philip Calvert
·2009-08-12 06:07:18
this was all I could manage mathematically...
though looking at
m = - v / u carefully could 've settled things.
Also note that the condition u > 0 is necessary but not sufficient for m to be -ive
11
mona100
·2009-09-20 12:28:03
Whts the final answer? i think m can never be negtive for convex mirrors.