A body of mass $m$ collides against a wall with a velocity $v$ and rebounds with the same speed. Its change of momentum is
A body of mass $m$ collides against a wall with a velocity $v$ and rebounds with the same speed. Its change of momentum is
$2\, mv$
$mv$
$-mv$
Zero
A body of mass $m$ collides against a wall with a velocity $v$ and rebounds with the same speed. Its change of momentum is
$\Delta p = {p_i} - {p_f} = mv - ( - mv) = 2\,mv$