Q8 of 29 Page 65

Consider two cylindrical rods of identical dimensions, one of rubber and the other of steel. Both the rods are fixed rigidly at one end to the roof. A mass M is attached to each of the free ends at the centre of the rods.

Both rubber and steel rod will be subjected to same force, and will be elongated, but since, they have different elasticities, (steel being more elastic than rubber), steel rod doesn’t show any perceptible change in shape while the rubber rod elongates with the shape of the bottom edge tapered to a tip at the centre.

More from this chapter

All 29 →
6

A mild steel wire of length 2L and cross-sectional area A is stretched, well within elastic limit, horizontally between two pillars (Fig. 9.1). A mass m is suspended from the midpoint of the wire. Strain in the wire is


 7

A rectangular frame is to be suspended symmetrically by two strings of equal length on two supports (Fig. 9.2). It can be done in one of the following three ways;

(a)


(b)


(c)


The tension in the strings will be


 9

The stress-strain graphs for two materials are shown in Fig.9.3 (assume same scale).


 10

A wire is suspended from the ceiling and stretched under the action of a weight F suspended from its other end. The force exerted by the ceiling on it is equal and opposite to the weight.