Question

a man hits golf ball (2kg) which accelerates at a rate of 20 m/s/s what amount of force acted on the ball

Answer 1

Force = (mass) x (acceleration)

= (2 kg) x (20 m/s²) = 40 newtons .

about 9 pounds .

Note: The ball can only accelerate during the short time
that the clubface is in contact with it. Once it leaves the
clubface, it can't accelerate any more.

Also ... that's one heckuva golf ball. It weighs about 4.4 pounds !