A bullet of mass 20 g has an initial speed of 1 m s - 1 , just before it starts penetrating a mud wall of…

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

Solution

a=-2.5×10-220×10-3=-54 m s-2
From v2-u2=2as
v2=u2+2as
v=12-2×54×20×10-2
=0.5
=0.7 m s-1

Asked in: JEE Main 2019 (10 Apr Shift 2)

Practice more Motion In One Dimension questions on Aicharya