Answer to Question #226255 in Physics for Diligent

Question

A body of mass 40kg is given an acceleration of 10 meter per seconds on a horizontal ground for which m=0.5. Calculate the force required to accelerate to the body.( take g=10 meter per seconds )

Answer 1

According to Newton's second law:

$$ma=F-f,\\ ma=F-\mu mg,\\\space\\ F=ma+\mu mg=m(a+\mu g)=596\text N.$$

Actually, the force of friction is

$$f=\mu N,$$

where N - normal force. But since the body is on a horizontal surface, we can state that

$$N=mg.$$