Question

A bullet of 5g , travelling at a speed of 100 m/s penetrates a wooden block up to 6.0 cm. Then the average force applied by the bullet on the block is-<br />a) 417 N<br />b) 8333 N<br />c) 83.3 N<br />d) 0​

Answer 1

EXPLANATION.

A bullet of 5 gram travelling at a speed of

100 m/s.

it penetrate a wooden block upto 6.0 cm.

To find the average force applied by

the bullet on the block.

According to the question,

=> mass of a bullet = 5 gram = 0.005 kg.

=> velocity = 100 m/s.

$\rm \to \: initial \: kinetic \: energy \: = k.e_{i} = \frac{1}{2}m {v}^{2}$

$\rm \to \: \frac{1}{2} \times 0.005 \times 100 \times 100$

=> 25 joule.

=> final velocity = 0

$\rm \to \: final \: kinetic \: energy \: = k.e_{f} \: = \frac{1}{2} m {v}^{2}$

$\rm \to \: \frac{1}{2} \times 0.005 \times 0 \times 0$

=> 0 joule.

=> Distance = 6.0 cm. = 0.06 m.

$\rm \to \: force \: exerted \: by \: bullet \: = f.s \: = | ke_{f} - ke_{i} |$

=> F X 0.06 = | 0 - 25 |

=> F = 417 N.