Final answer:
When a person makes a 'aaagh' noise while making an effort, such as trying to hit a ball hard, it is because of the transfer of momentum between the object and the person's body.
Step-by-step explanation:
When a person makes a 'aaagh' noise while making an effort, such as trying to hit a ball hard, it is because of the transfer of momentum between the object and the person's body. According to Newton's third law of motion, for every action, there is an equal and opposite reaction. When the person exerts a force on the object (e.g.- hitting a ball), the object exerts an equal and opposite force on the person. This force causes the person to react by making the 'aaagh' noise as they exert effort.