A 110 g ball has a kinetic energy 39.8 J.

What's the magnitude of its momentum?
Use your answer to find its speed.

K=p^2/2m
39.8=p^2/(2*110)
8756=p^2
p=93.5735 kg*m/s

^this is wrong though. where did I go wrong?

the decimal point on the mass units is incorrect

Joules uses kilograms, not grams

you used kg in the momentum, but not the K