Question

2. A man of mass 60 kg carries a bag of weight 60 N
on his shoulder. Find the force with which the floor
pushes up his feet.

Answer 1

Given

Weight of man = 60kg

Weight of bag in men carries on his shoulder = 60N

To find

Force with which the floor

pushes up his feet = ?

Solution

We know that,

Weight of bag = 60N

G × mass of bag = 60N

Where G is the acceleration due to gravity = 9.8 sq ms

Let

m1 = mass of bag

$m1 = \frac{60}{9.8} \: kg \\ m1 = 6.08 \: kg$

m2 = mass of man i.e., 60 kg

Total mass of man and bag system = (60+6.08) kg

= 66.08 kg

Free Body Diagram

[given]

Where,

N = Normal reaction that applies at static equilibrium

N = (m1 + m2) g

N = 66.08 × 9.8

N = 647.584

Therefore,

the force with which the floor

pushes up his feet = 647.584N

Answer 2

Given

Weight of man = 60kg

Weight of bag in men carries on his shoulder = 60N

To find

Force with which the floor

pushes up his feet = ?

Solution

We know that,

Weight of bag = 60N

G × mass of bag = 60N

Where G is the acceleration due to gravity = 9.8 sq ms

Let

m1 = mass of bag

m2 = mass of man i.e., 60 kg

Total mass of man and bag system = (60+6.08) kg

= 66.08 kg

Free Body Diagram

[given]

Where,

N = Normal reaction that applies at static equilibrium

N = (m1 + m2) g

N = 66.08 × 9.8

N = 647.584

Therefore,

the force with which the floor

pushes up his feet = 647.584N