Define impulse and state the impulse–momentum theorem.

Define impulse and state the impulse–momentum theorem.

• A. Impulse J = ∫ F dt; J = Δp
• B. Impulse is equal to work done
• C. Impulse is equal to momentum
• D. Impulse is the rate of energy change

Answer: (A)

Impulse is the total “kick” a force gives to an object’s motion, measured as the change in momentum. It’s defined as the integral of the force over the time the force acts: J = ∫ F dt. If the force is constant, this becomes J = F Δt. Because force changes momentum (F = dp/dt), integrating both sides over the time interval yields ∫ F dt = Δp. So the impulse–momentum theorem states that impulse equals the change in momentum: J = Δp = p_f − p_i. In units, impulse is Newton-seconds (N·s) or kg·m/s. This is distinct from work, which is the integral of F · dx and relates to energy, while impulse directly changes momentum, not energy.

Impulse is the total “kick” a force gives to an object’s motion, measured as the change in momentum. It’s defined as the integral of the force over the time the force acts: J = ∫ F dt. If the force is constant, this becomes J = F Δt. Because force changes momentum (F = dp/dt), integrating both sides over the time interval yields ∫ F dt = Δp. So the impulse–momentum theorem states that impulse equals the change in momentum: J = Δp = p_f − p_i. In units, impulse is Newton-seconds (N·s) or kg·m/s. This is distinct from work, which is the integral of F · dx and relates to energy, while impulse directly changes momentum, not energy.