Question

A bullet moving with 10m/s and brought to rest penetrating the wood plank of 4 cm thick calculate retardation?
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Answer 1

Answer:

v2-u2=2as

-100=0.08a

a=- 1250m/s2

Answer 2

Given :-

A bullet moving with 10m/s and brought to rest penetrating the wood plank of 4 cm thick.

To Find :-

The retardation of the bullet.

Solution :-

We know that,

• u = Initial velocity
• s = Displacement
• a = Acceleration
• v = Final velocity

By the third law of motion,

$\underline{\boxed{\sf v^{2}=u^{2}+2as}}$

Initial velocity (u) = 10 m/s

Displacement (s) = 4 cm

Final velocity = 0

Substituting their values,

$\sf 0=10^{2} \times 2 \times a\times 0.04$

$\sf -100=0.08a$

Finding a,

$\sf a=\dfrac{100}{0.08}$

$\sf a=-1250 \ m/s^{2}$

Therefore, the retardation of the bullet is -1250 m/s²