Applied Mechanics - Engineering

Q1:

A block of weight 50 kg is placed on a horizontal plane. When a horizontal force of 18 kg is applied, the block is just on the point of motion. The angle of friction is

A 17° 48'

B 18° 48'

C 19° 48'

D 20° 48'

E 21° 48'

ANS:C - 19° 48'

Angle of friction,
tanA = maximum force of friction/normal reaction.
tanA = 18/50 = 0.36.
A = tan (0.36) = 19' 48'.