What is the value of P before for the box tips and slips Tip

What is the value of P before for the box tips and slips? Tipping, P = 0.854 lb; sliding, P = 3.12 lb Tipping, P = 0.369 lb; slides without any P load Tipping, P = 0.369 lb; sliding, P = 1.34 lb Tipping, P = 0.243 lb; sliding, P = 0.45 lb Tipping, P = 0.415 lb; sliding, P = 1.38 lb A rod has a weight of 60 N and is leaning on a smooth wall at point A. If the ground surface at B has a friction coefficient, mu = 0.2, what is the minimum force F that will keep the rod from slipping? 160 N 40 N 100 N 70 N 0 N

Solution

5.

Length of ladder = sqrt(1.5^2 + 1^2) = 1.8 m

Weight 60 N acts at mid-point.

Horizontal distance between ladder mid-point and wall = (0.4+0.6)/2 = 0.5 m

X = Horizontal direction

Y = Vertical Direction

Reactions at A be Ax and Ay.

Reactions at B be Bx and By.

Friction force Bx = -0.2*By

Since wall is smooth, Ay = 0

Balancing forces in x-direction, Ax + Bx = 0

Ax = 0.2*By

Balancing forces in y-direction, By + F - 60 = 0

By = 60 - F

Balancing moments about B, Ax*1.5 - 60*0.5 + F*0.6 = 0

0.2*1.5*By - 30 + F*0.6 = 0

0.2*1.5*(60-F) - 30 + F*0.6 = 0

F = 40 N