JUCA
76. A gun of mass M fires a bullet of mass m with a
horizontal speed V. The gun is fitted with a concave
mirror of focal length f facing towards the receding
bullet. Find the speed of separation of the bullet and the
image just after the gun was fired.
Answers
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12th
Physics
Ray Optics and Optical Instruments
Problems on Mirror and Magnification Formula
A gun of mass 'm1 ' fires a...
PHYSICS
A gun of mass
′
m
1
′
fires a bullet of mass
′
m
2
′
with a horizontal speed
′
v
0
′
. The gun is fitted with a concave mirror of focal length f facing toward a receding bullet. Find the speed of separation of the bullet and the image just after the gun was fired
November 22, 2019avatar
Ashi Vardhan
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ANSWER
v
1
+
u
1
=
f
1
u=−u ; f=−f
v=
f−u
fu
wrt to gun the image velocity is
d
t
d
v
=
d
t
d
f−u
fu
=
(f−u)
2
f
2
×v
o
as u=0( just after impact)
d
t
d
v
=v
o
Speed of separation of the bullet and the image just after the gun was fired = velocity of image + velocity of bullet
Speed of mirror =
m
1
m
2
v
o
wrt to ground ,
Speed of bullet = speed of bullet wrt mirror + speed of mirror
=v
0
+
m
1
m
2
v
o
Speed of image=speed of image wrt mirror +speed of mirror
=v
0
+
m
1
m
2
v
o
Speed of separation of the bullet and the image just after the gun was fired=2(v
0
+
m
1
m
2
v
o
Type your question...
12th
Physics
Ray Optics and Optical Instruments
Problems on Mirror and Magnification Formula
A gun of mass 'm1 ' fires a...
PHYSICS
A gun of mass
′
m
1
′
fires a bullet of mass
′
m
2
′
with a horizontal speed
′
v
0
′
. The gun is fitted with a concave mirror of focal length f facing toward a receding bullet. Find the speed of separation of the bullet and the image just after the gun was fired
November 22, 2019avatar
Ashi Vardhan
SHARE
ANSWER
v
1
+
u
1
=
f
1
u=−u ; f=−f
v=
f−u
fu
wrt to gun the image velocity is
d
t
d
v
=
d
t
d
f−u
fu
=
(f−u)
2
f
2
×v
o
as u=0( just after impact)
d
t
d
v
=v
o
Speed of separation of the bullet and the image just after the gun was fired = velocity of image + velocity of bullet
Speed of mirror =
m
1
m
2
v
o
wrt to ground ,
Speed of bullet = speed of bullet wrt mirror + speed of mirror
=v
0
+
m
1
m
2
v
o
Speed of image=speed of image wrt mirror +speed of mirror
=v
0
+
m
1
m
2
v
o
Speed of separation of the bullet and the image just after the gun was fired=2(v
0
+
m
1
m
2
v
o
)