Question

A bullet of mass 20g has a initial speed of 1m second inverse,just before it starts penetrating a mud wall of thickness 20cm.if the wall offers a mean resistance of2.5 10power -2, the speed of the bullet after emerging from the other side of the wall is close to

Answer 1

Given:

The mass of the bullet m= 20 g

Speed of the bullet v= 1 m/sec

The thickness of wall is 20 cm

The resistance of the 2.5×10⁻²

To find:

The speed of the bullet from the other side of the wall.

Solution:

The formula of force is

F=ma

a= F/m

a= -2.5×10⁻²/20×10⁻³

Now using the equation of motion formula

v²=u²+2as

v²=1-2.5×10⁻²×20/20×10⁻³×100

v=1/√2

v=0.7 m/sec

So the speed of the other bullet is 0.7 m/sec