Advertisements
Advertisements
Question
The yield point of a typical solid is about 1%. Suppose you are lying horizontally and two persons are pulling your hands and two persons are pulling your legs along your own length. How much will be the increase in your length if the strain is 1% ? Do you think your yield point is 1% or much less than that?
Advertisements
Solution
Let my length = L
Let the increase in length = l
Strain
\[= \frac{l}{L} = \frac{1}{100}\]
\[ \Rightarrow \text{ l }= \frac{L}{100}\]
\[\text{ So, the increase in length will be } \frac{L}{100} .\]
Yes, the yield point is much less than the 1% strain because the human body consists of joints and not one uniform solid structure.
APPEARS IN
RELATED QUESTIONS
A steel cable with a radius of 1.5 cm supports a chairlift at a ski area. If the maximum stress is not to exceed 108 N m–2, what is the maximum load the cable can support?
When a block a mass M is suspended by a long wire of length L, the elastic potential potential energy stored in the wire is `1/2` × stress × strain × volume. Show that it is equal to `1/2` Mgl, where l is the extension. The loss in gravitational potential energy of the mass earth system is Mgl. Where does the remaining `1/2` Mgl energy go ?
When the skeleton of an elephant and the skeleton of a mouse are prepared in the same size, the bones of the elephant are shown thicker than those of the mouse. Explain why the bones of an elephant are thicker than proportionate. The bones are expected to withstand the stress due to the weight of the animal.
A steel blade placed gently on the surface of water floats on it. If the same blade is kept well inside the water, it sinks. Explain.
The breaking stress of a wire depends on
A heave uniform rod is hanging vertically form a fixed support. It is stretched by its won weight. The diameter of the rod is
Modulus of rigidity of ideal liquids is ______.
The maximum load a wire can withstand without breaking, when its length is reduced to half of its original length, will ______.
A spring is stretched by applying a load to its free end. The strain produced in the spring is ______.
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.
A rod of length l and negligible mass is suspended at its two ends by two wires of steel (wire A) and aluminium (wire B) of equal lengths (Figure). The cross-sectional areas of wires A and B are 1.0 mm2 and 2.0 mm2, respectively.
(YAl = 70 × 109 Nm−2 and Ysteel = 200 × 109 Nm–2)
- Mass m should be suspended close to wire A to have equal stresses in both the wires.
- Mass m should be suspended close to B to have equal stresses in both the wires.
- Mass m should be suspended at the middle of the wires to have equal stresses in both the wires.
- Mass m should be suspended close to wire A to have equal strain in both wires.
Is stress a vector quantity?
If 'S' is stress and 'Y' is young's modulus of the material of a wire, the energy stored in the wire per unit volume is ______.
A body of mass m = 10 kg is attached to one end of a wire of length 0.3 m. The maximum angular speed (in rad s-1) with which it can be rotated about its other end in the space station is (Breaking stress of wire = 4.8 × 107 Nm-2 and the area of cross-section of the wire = 10-2 cm2) is ______.
What is an elastomer?
Answer in one sentence:
What is an elastomer?
Strain is defined as the ratio of ______.
