Question

why pulling the lawn roller os preferred than pushing the lawn roller

Answer 1

consider a lawn roller pulled by a force F which makes an angle θ with the horizontal.the weight mg acts vertically downwards and normal reaction N acts vertically upwards

let the force F be resolved into two components .the component Fsinθ acts vertically upwards and the other component Fcosθ acts in horizontal direction .in this case normal reaction N=mg-Fsinθ

frictional force=f=myu N......................1

PUSHING -N=mg+Fsinθ

f=myu N

f=myu[mg+Fsinθ]..............................2

from 1and 2 we see that frictional force is more in pushing than pulling

hence it is easier to pull than push a lawn roller