Choose all that apply a the force P could be acting in the o

Choose all that apply

a the force P could be acting in the opposite direction

b the deformation of rod 1 must be negative

c

the deformation of rod 1 must be positive

d the temperature may have decreased

e the temperature may have increased

Choose all that apply a the force P could be acting in the opposite direction

A rigid bar ABCD is pinned at A and supported by two steel rods connected at B and C. If the deformation of rod 2 is found to be negative, list the possible explanations and effects of this deformation 2.7 m 1.5 m Rigid bar 2.0 m 25 m 0.5 m

Solution

Options (a), (b) and (d) are correct.

Explanation: (a) If P is negative then the force acts upwards, therefore the compressive stresses gets induced in both the the rods, and therefore the rods gets compresed to shorter lengths than original, therefore the deformation becomes -ve.

(b) If somehow the deformation in smaller rod is -ve, then deformation in longer rod also must be -ve because the bar is rigid and it can not deform, so longer rod has to deform in the same direction as that of shorter one.

(c) When temperature is decreased, the temperature stresses gets induced if rods are rigid at both ends. Now if the temperature stress induced becomes greater than the stress due to load P, then rod will have a -ve deformation.