A bullet fired from a gun with a velocity of 104 ms -1 goes through a bag full of straw. If the bullet loses half of its kinetic energy in the bag, its velocity when it comes out of the bag will be

Question

A bullet fired from a gun with a velocity of 104 ms -1 goes through a bag full of straw. If the bullet loses half of its kinetic energy in the bag, its velocity when it comes out of the bag will be (A) 7071.06 ms -1 (B) 707 ms -1 (C) 70.71 ms -1 (D) 707.06 ms -1

Tardigrade Admin · Accepted Answer

KE left, (1/2) m v2=(1/2)((1/2) m u2) ∴ Velocity left, v=(u/√2)=(104/√2) =7071.06 ms -1

Q. A bullet fired from a gun with a velocity of $1 0^{4} m s^{- 1}$ goes through a bag full of straw. If the bullet loses half of its kinetic energy in the bag, its velocity when it comes out of the bag will be

$7071.06 m s^{- 1}$

$707 m s^{- 1}$

$70.71 m s^{- 1}$

$707.06 m s^{- 1}$

$K E$ left, $\frac{1}{2} m v^{2} = \frac{1}{2} (\frac{1}{2} m u^{2})$
$∴$ Velocity left, $v = \frac{u}{2} = \frac{1 0 ^{4}}{2}$
$= 7071.06 m s^{- 1}$

Q. A bullet fired from a gun with a velocity of 104ms−1 goes through a bag full of straw. If the bullet loses half of its kinetic energy in the bag, its velocity when it comes out of the bag will be

7071.06ms−1

707ms−1

70.71ms−1

707.06ms−1