A bullet of mass 20 g has an initial speed of $1 \mathrm {~m} \mathrm {~s} ^ { - 1 }$, just before it starts penetrating a mud wall of thickness 20 cm . If the wall offers a mean resistance of $2.5 \times 10 ^ { - 2 } \mathrm {~N}$, the speed of the bullet after emerging from the other side of the wall is close to: (1) $0.7 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ (2) $0.3 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ (3) $0.1 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ (4) $0.4 \mathrm {~m} \mathrm {~s} ^ { - 1 }$
A bullet of mass 20 g has an initial speed of $1 \mathrm {~m} \mathrm {~s} ^ { - 1 }$, just before it starts penetrating a mud wall of thickness 20 cm . If the wall offers a mean resistance of $2.5 \times 10 ^ { - 2 } \mathrm {~N}$, the speed of the bullet after emerging from the other side of the wall is close to:\\
(1) $0.7 \mathrm {~m} \mathrm {~s} ^ { - 1 }$\\
(2) $0.3 \mathrm {~m} \mathrm {~s} ^ { - 1 }$\\
(3) $0.1 \mathrm {~m} \mathrm {~s} ^ { - 1 }$\\
(4) $0.4 \mathrm {~m} \mathrm {~s} ^ { - 1 }$