Force on a bullet is F = 600 − 2 × 10⁵t, where F is in newtons and t is in seconds. When the force on the bullet is zero, the impulse is ______ N s.
Physics · Mixed Chapter
JEE Main Practice

Question

Force on a bullet is F = 600 − 2 × 10⁵t, where F is in newtons and t is in seconds. When the force on the bullet is zero, the impulse is ______ N s.

G1 Physics · Accepted Answer

Step 1: Force becomes zero at 600 − 2 × 10⁵t₀ = 0. Step 2: Hence t₀ = 600/(2 × 10⁵) = 3 × 10⁻³ s. Step 3: Impulse is the integral of force over time from 0 to t₀: J = ∫ F dt = [600t − 10⁵t²] evaluated between 0 and t₀. Step 4: J = 600(0.003) − 10⁵(0.003)² = 1.8 − 0.9 = 0.9 N s. Final answer: 0.9 N s.