A bullet moving with a velocity of 800 m/s passes through two plates of
widths d, and d2. In passing through each of them, it loses a velocity of
200 m/s. If d, is 7 cm then, if both the plates offer same
then continues at constant speed for time t and then decelerates at the rate f/2 to come to rest. If the total distance traversed is 5 s, then, find
the ratio d1/d2
Answers
Explanation:
Given,
The initial velocity of the bullet is
v
i
=800ms
−1
Velocity of bullet after passing through x
1
v
x
1
=800−200=600ms
−1
And velocity of bullet after passing through x
2
v
x
2
=600−200=400ms
−1
Now, work done in passing through x
1
is equals to the loss in kinetic energy hence,
Fx
1
=
2
1
m((v
i
)
2
−(v
x
1
)
2
)............(1)
And work done in passing through x
2
is equals to the loss in kinetic energy hence,
Fx
2
=
2
1
m(v
x
1
)
2
−(v
x
2
)
2
...........(2)
Dividing (1) by (2), we get,
Fx
2
Fx
1
=
2
1
m[(v
x
1
)
2
−(v
x
2
)
2
]
2
1
m[(v
i
)
2
−(v
x
1
)
2
]
x
2
x
1
=
2
1
[(600)
2
−(400)
2
]
2
1
[(800)
2
−(600)
2
]
x
2
x
1
=
36−16
64−36
x
2
x
1
=
20
28
=
5
7
in the same way put given values accordingly to get result