JEE Main Physics 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
Answer: (A)
Solution
Half the KE is lost, so the remaining KE is half of the original: ½mv² = ½(½mu²) ⟹ v = u/√2 = 10⁴/√2 ≈ 7071.06 ms⁻¹.