What is can impulse be negative?

Yes, impulse can be negative.

• Definition: Impulse is defined as the change in momentum of an object. Mathematically, it is represented as:

  Impulse (J) = Force (F) × Time (Δt) = Change in momentum (Δp) = m × Δv = m × (vf - vi)

  where:

  • F is the force applied
  • Δt is the time interval during which the force is applied
  • m is the mass of the object
  • vf is the final velocity
  • vi is the initial velocity

• Vector Quantity: Impulse is a vector quantity, meaning it has both magnitude and direction. The direction of the impulse is the same as the direction of the net force acting on the object.

• Negative Impulse: A negative impulse indicates that the impulse is acting in the opposite direction to the object's initial motion or a designated positive direction. This occurs when the force applied is in the opposite direction of the object's velocity, causing it to slow down or change direction.

• Examples:

  • Braking: When a car brakes, the force applied by the brakes is in the opposite direction to the car's motion, resulting in a negative impulse. The negative%20impulse reduces the car's momentum.
  • Catching a Ball: When catching a ball, the force you apply to stop the ball's motion is opposite to the ball's velocity, resulting in a negative impulse that brings the ball to rest.
  • Collision: In a collision, if an object bounces back in the opposite direction, the impulse it experiences can be considered negative relative to its initial direction.

• Sign Convention: The sign of the impulse depends on the chosen coordinate system. If a direction is defined as positive, then an impulse acting in the opposite direction will be negative.