Question

A man of mass 50 kg carries a bag of weight 40N on his shoulder. The force with which the floor pushes up his feet will be

Answer 1

Given, Weight = 40N and mass= 50 Kg.


We know that, F=ma  

                        40N = m x g

                        40/g = m

                       40/10 = m

                       4kg = m

                     mass = mass of man + mass of bag

                              = 50 + 4

                             = 54 kg

Force with which the floor pushes up his feet,
                       
                       F = ma

                      F  = 54 x g

                      F = 54 x 10

                         = 540N.


Hope this helps!

Answer 2

mass of man =  50 kg 

weight of bag = 40 N , = mass x acceleration due to gravity = 4 x 10 

mass of bag = 4 Kg 

Force with which floor pushes up his feet =( mass of man + mass of bag ) g 

(50 + 4) 10 = 540 N