Final answer:
The force exerted by the soccer player on the 400g soccer ball, which accelerates at 5 m/s2, is calculated using Newton's second law and is 2 Newtons.
Step-by-step explanation:
To calculate the force exerted by the soccer player on the ball, we use Newton's second law, which states that force equals mass times acceleration (F = m*a). Given that the soccer ball has a mass of 0.4 kg and it accelerates at 5 m/s2, the force can be calculated as follows:
F = m * a
F = 0.4 kg * 5 m/s2
F = 2 N
Therefore, the force that the soccer player needs to exert on the 400g soccer ball to achieve an acceleration of 5 m/s2 is 2 Newtons.