a=−20×10−32.5×10−2=−45ms−2
From v2−u2=2as
v2=u2+2as
v=12−2×45×20×10−2
=0.5
=0.7ms−1
A bullet of mass 20g has an initial speed of 1ms−1, just before it starts penetrating a mud wall of thickness 20cm. If the wall offers a mean resistance of 2.5×10−2N, the speed of the bullet after emerging from the other side of the wall is close to:
Held on 10 Apr 2019 · Verified 6 Jul 2026.
0.7ms−1
0.3ms−1
0.1ms−1
0.4ms−1
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