Question

WHAT IS THE ANSWER ?? WHAT IS THE ANSWER ??WHAT IS THE ANSWER??​

Answer 1

$\huge{\bold{\underline{\underline{....Answer....}}}}$

$\huge{\bold{\underline{Given:-}}}$

Mass of Bullet (m) = 10 grams = 0.01 Kg.

Initial Speed of Bullet (u) = 10³ m/s.

Final velocity of bullet (v) = 0 m/s.

Distance (S) = 5 cm = 0.05 m.

$\huge{\bold{\underline{Explanation:-}}}$

1) Resistive Force :-

Firstly we need to find acceleration.

Using third kinematic equation,

$\large{\bold{v^2 - u^2 = 2as}}$

Substituting the values,

$\large{(0)^2 - (10^3)^2 = 2 \times a \times 0.05 }$

$\large{0 - 10^6 = 0.1 \times a}$

$\large{a = \frac{ - 10^6}{0.1}}$

$\large{\boxed{a = - 10^7 \: m/s^2}}$

Now, Newton's second law,

$\large{\bold{F = ma}}$

Substituting the values,

$\large{F = 0.01 \times - 10^7}$

$\large{F = 1 \times 10^{-2} \times - 10^7}$

$\huge{\boxed{\boxed{F = - 10^5 \: N}}}$

Here the negative sign indicates that Force is acting against the motion of the body.

So, the average resistive force which acts on the bullet is 10⁵N.

2)Time Taken by the Bullet to come to rest is :-

Using First kinematics equation ,

$\large{\bold{v = u + at}}$

Substituting the values,

$\large{0 = 10^3 + (- 10^5)t}$

$\large{10^5 \times t = 10^3}$

$\large{t = \frac{10^3}{10^5}}$

Now,

$\large{t = 10^{(3 - 5)}}$

$\large{t = 10^{-2}}$

$\huge{\boxed{\boxed{t = 0.01 \: Second}}}$

So,the bullet comes to rest in 0.01 seconds.

Answer 2

1.Resestive force:-

Firstly we need to find acceleration.

Using thrird kinematic equation,

V²-u²=2as

substituting the values,

(0)²- (10³)²=2×a×0.05

0-10⁶=0.1×a

a=-10⁶/0.1

a=10⁷m/s²

Now Newton' second law

F=ma

Substituting the values

F=0.01×-10⁷

F=1×10-2×-10⁷

F=-10⁵N

Hence the negative sign indicates that force is acting against the motion of the body.

So the average resistive force which acts on the bullet is10⁵N

2.Time taken by the bullet to come to rest is :-

using first kinematics equation

v=u+at

substituting the values

0=10³+(-10⁵)t

10⁵×t=10³

t=10³/10⁵

Now,

t=10(³-⁵)

t=10-²

t=0.01 seconds

so,the bullet comes to rest in 0.01 seconds