A 70-kg man pushes a 50-kg man by a force of 50N. By what force has the 50-kg man pushed the other man?
Answers
Given condition,
Mass of the man = 70kg
(F) Force used by the man to push another man of mass 50 kg = 50 N.
Normal reaction act on 50 kg man = mass × acceleration due to gravity.
= 50 × 10 N
= 500 N
Using the Formula, Friction = r N ,
where,
N is normal reaction,
r is coefficient of static friction
In Ideal Condition, Frictional Force = Normal Reaction Force.
∴ 50 = r × N
50 = r × 500
⇒ r = 0.1
∴ coefficient of static Friction = 0.1
Let the Force acting on the man of mass 50 kg by the man of mass 70 kg be x.
∴ x = static Friction
x = coefficient of static friction × normal reaction act on 70 kg man
x = 0.1 × 70 × 10
x = 70 N
Hence, the Force of 70 N acts on the body of mass 50 kg by the man of 70 kg is 70 N.
Hope it helps.
Given:
Mass of man1 = 70 kg
Mass of man2 = 50 kg
Force = 50 N
To find:
The force needed by man2 to push man1
Solution:
By formula,
Normal= Mass * Gravity
Where,
Gravity = 9.8 m / s
Substituting,
50 × 9.8
Normal = 490 N
To find friction,
Friction = r * Normal
Where,
r is coefficient of static friction
We know,
Ideally,
Frictional Force = Normal Reaction Force.
∴ 50 = r × N
50 = r × 490
r = 0.102
Hence,
Force = 0.102 × 70 × 9.8
Force = 69.9 N
Therefore, Force ≅ 70 N