18. The rod shown in the figure pivots around an axle at the left end. With forces applied as
nnoted, the net torque, in N.m, is:
a) +60
b) -60
d) +20
e) -20
c) +40
100 N
2 m
1 m
40 N
60 N
19. For an object in static equilibrium, which statement is correct
a) The net torque must be zero only at point A
b) The net torque must be zero only at point C
c) The net torque must be zero only at point B
d) The net torque must be zero only at points C and D
e) The net torque must be zero at all points
D
20. If we have 4 objects (1, 2, 3, 4) where their critical angle $\theta_c$ that govern their stability
follows this relation $\theta_{c1} > \theta_{c2} > \theta_{c3} > \theta_{c4}$, accordingly the most stable object is:
a) Object 1
b) Object 2
d) Object 4
c) Object 3
e) All the objects have the same stability
