Answer

Verified

347.4k+ views

**Hint:**When a bullet is fired and it starts to penetrate in a target, then it will cover some distance with negative acceleration and its final velocity will be zero and we will determine the additional thickness bullet will penetrate by using newton’s equation of motion ${v^2} - {u^2} = 2aS$.

**Complete step by step answer:**

Let us assume in first $30\,cm$ penetration the initial velocity of bullet was $u$ and final velocity behalf of initial velocity as it’s given so we can write as $v = \dfrac{u}{2}$

$S = 0.3\,m$

Now, putting these values in equation ${v^2} - {u^2} = 2aS$ we get,

$\dfrac{{{u^2}}}{4} = {u^2} + 2a(0.3)$

$\Rightarrow \dfrac{{ - 3{u^2}}}{4} = 0.6a \to (i)$

Now, let us assume the bullet further penetrate through distance say $S'$ and final velocity in this case will be zero as bullet will came to rest and initial velocity will be $\dfrac{u}{2}$ , putting these values in equation ${v^2} - {u^2} = 2aS$ we get,

$\dfrac{{ - {u^2}}}{4} = 2aS' \to (ii)$

From equations $(i)and(ii)$ we can write as:

$S' = 0.1\,m$

$\therefore S' = 10\,cm$

So, the thickness to which bullet will further penetrate the target is $S' = 10cm$

**Hence, the correct option is B.**

**Note:**It’s important to remember that, the final velocity with which first $30cm$ penetration happen will became the initial velocity of final penetration of $10cm$ and other two equations of motion as $v = u + at$ , $S = ut + \dfrac{1}{2}a{t^2}$ . These three equations are called newton’s equation of motion and whole classical mechanics of motion can be understand through these equations.>

Recently Updated Pages

How many sigma and pi bonds are present in HCequiv class 11 chemistry CBSE

Why Are Noble Gases NonReactive class 11 chemistry CBSE

Let X and Y be the sets of all positive divisors of class 11 maths CBSE

Let x and y be 2 real numbers which satisfy the equations class 11 maths CBSE

Let x 4log 2sqrt 9k 1 + 7 and y dfrac132log 2sqrt5 class 11 maths CBSE

Let x22ax+b20 and x22bx+a20 be two equations Then the class 11 maths CBSE

Trending doubts

Which are the Top 10 Largest Countries of the World?

The 3 + 3 times 3 3 + 3 What is the right answer and class 8 maths CBSE

Fill the blanks with the suitable prepositions 1 The class 9 english CBSE

How many crores make 10 million class 7 maths CBSE

Difference Between Plant Cell and Animal Cell

Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE

Give 10 examples for herbs , shrubs , climbers , creepers

Change the following sentences into negative and interrogative class 10 english CBSE

Write a letter to the principal requesting him to grant class 10 english CBSE