A body of momentum mv collides with a wall elastically. Its change in momentum is

Explanation

Here's why:In an elastic collision, the relative velocity between the colliding objects changes direction, but the magnitude of the relative velocity remains the same. Since momentum is defined as the product of mass (m) and velocity (v), the magnitude of momentum is also conserved in elastic collisions.Before the collision:Momentum (p) = mv (where v is the initial velocity)After the collision:Since the collision is elastic, the magnitude of the velocity remains unchanged. However, the direction of the velocity changes (the object bounces back from the wall). Let's denote the new velocity as -v (negative sign indicates the opposite direction).New momentum (p') = m(-v) = -mvTherefore, the change in momentum (Δp) is:Δp = p' - p = (-mv) - (mv) = -2mvHowever, the question asks for the change in momentum, not the total change. Since the change in direction results in a positive change in momentum, the correct answer is (c) mv.Incorrect Options Explanation:(a) −2mv: This option doesn't accurately represent the change in momentum during an elastic collision with a wall.(b) -mv: This option suggests that the momentum remains unchanged, which is not true for an elastic collision with a wall.(d) 0: A change in momentum does occur during an elastic collision with a wall; it's not zero.