Question

A 70 kg soccer player, running at 10m/s, kicks a 0.4kg ball, which then travels at 50m/s. the ball is then kicked back towards the player, so that it is now traveling in the opposite direction with the same speed. has the linear momentum of the ball changed?

A. no, the same mass and speed means the same linear momentum.
B. no, the same mass and opposite velocity means the same linear momentum.
C. yes, the same mass but a different velocity means a different linear momentum.
D. impossible to determine without knowing the force acting on the ball during the kick.

Answer 1

Linear momentum of an object changes if either the speed or the direction of its velocity changes. Here, because the direction of the soccer ball's velocity changed but the speed stayed the same, the linear momentum has changed.

Step-by-step explanation:

The question asks if the linear momentum of a soccer ball has changed after being kicked back toward the player in the opposite direction but with the same speed. Since linear momentum is a vector quantity, which means it has both magnitude (speed) and direction, a change in direction while maintaining the same speed does indeed change the linear momentum. Therefore, the correct answer is C. yes, the same mass but a different velocity means a different linear momentum.