Question

6. A man is riding a bike with an acceleration of 5.0 meters per second and a mass of the bike and him combined is 20 kg. What force is produced?

Answer 1

Newton's 2nd law of motion:

                         Force = (mass) x (acceleration)

For this man
on his bike:        Force = (20 kg) x (5 m/s²)

                                    =    100 newtons .

This is NOT the "force produced".

This is the force NEEDED in order to accelerate THAT man
and his bike at THAT rate.  If you don't have something that
can apply THAT force, then you can't create this situation,
and he'll just have to carry on, in the same direction and at
the same speed, without turning, slowing down, or speeding up.