I have these two problems and I cant seem to find the right answer...(adsbygoogle = window.adsbygoogle || []).push({});

1)A person with a blackbelt in karate has a fist that has a mass of 0.43 kg. Starting from rest, this fist attains a velocity of 5.9 m/s in 0.25 s. What is the magnitude of the average net force applied to the fist to achieve this level of performance?

2)When a 58 g tennis ball is served, it accelerates from rest to a constant speed of 43 m/s. The impact with the racket gives the ball a constant acceleration over a distance of 39 cm. What is the magnitude of the net force acting on the ball?

I know the answers are in N, but i've tried using F=ma which hasn't worked...maybe i am confused about what the magnitude of a net force is...please help!

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# Homework Help: Magnitude of a net force?

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