What is the acceleration of a 40-kg block of cement when pulled side ways, with a net force of 200 Newtons?

When you say "net" force, I understand that to mean that the effects of friction,

air resistance, the guy who is pulling it, etc. have all been taken into account,

and they all add up to 200 N. That's great! All we have to do then is apply

Newton's 2nd law to the situation, and we'll be instant heroes:

F = M A

A = F / M = 200 N / 40 kg = 5 meters per second-squared

f=ma

where m=40

f=200

a=f/m

a=200/40

a=5 m/s²