on what part on the field does he grow potatoes
Answers
Step-by-step explanation:
object distance(u) = - 30 cm
( object distance of an object placed in front of mirror is always negative as distances are always measured from the pole of the mirror)
the size of the image is 3 times the size of the object
hi =-3 ho
(as the object is real the image formed must be inverted hence height of the image is negative)
we know that ,
m = - \frac{v}{u} = \frac{hi}{ho}m=−
u
v
=
ho
hi
- \frac{v}{u} = - \frac{3ho}{ho}−
u
v
=−
ho
3ho
v = 3uv=3u
v = 3 \times - 30 = - 90cmv=3×−30=−90cm
As per the mirror formula,
\frac{1}{f} = \frac{1}{v} + \frac{1}{u}
f
1
=
v
1
+
u
1
\frac{1}{f} = \frac{1}{ - 90} + \frac{1}{ - 30}
f
1
=
−90
1
+
−30
1
\frac{1}{f} = \frac{ - 3 - 1}{90}
f
1
=
90
−3−1
\frac{1}{f} = \frac{ - 4}{90}
f
1
=
90
−4
f = 22.5cmf=22.5cm
Answer:
under thfield...............