Physics | JEE/NEET | Numericals on Elasticity | Lecture 3
Channel: Venkat Punjabi (VgyanHub Physics)
Date: 2023-12-19

Physics | JEE/NEET | Numericals on Elasticity | Lecture 3

0:04  A metal wire of length L1 and area of cross-section A is attached to a rigid support. Another metal wire of length 2 L and of the same cross-sectional area is attached to the free end of the first wire. A body of mass M is then suspended from the free end of the second wire. If Y1 and 2 Y are the Young’s moduli of the wires respectively, the effective force constant of the system of two wires is

8:33 Four identical hollow cylindrical columns, support a big structure of mass M. The inner and another radii of a column are 1 R and 2 R respectively. Assuming the load distribution to be uniform, the compressional strain of each column is (where Y is Young’s modulus of the column)

16:17 If the work done in stretching a wire by 1 mm is 2J the work necessary for stretching another wire of same material but with double radius of cross section and half the length by 1mm is.

20:18 The average depth of Indian ocean is about 3000 m. The fractional compression,
V V of water at the bottom of the ocean is (Given : Bulk modulus of the water 9 2 2 2.2 10 N m and g m s 

23:56 A square lead slab of side 50 cm and thickness 10 cm is subjected to a shearing force (on its narrow face) of 9 10 N. 4  the lower edge is riveted to the floor. How much will the upper edge be displaced? (Shear modulus of lead 5.6 10 N m )

34:33 The area of a cross-section of steel wire is 2 0.1 cm and Young’s modulus of steel is 2 10 N m . 11 2  The force required to stretch by 0.1% of its length is

39:19 A steel wire of length 4.5 m and cross-sectional area 5 2 3 10 m   stretches by the same amount as a copper wire of length 3.5 m and cross-sectional area 5 2 4 10 m   of under a given load. The ratio of the Young’s modulus of steel to that of copper is

42:08  A sphere contracts in volume by 0.01%, when taken to the bottom of sea 1 km deep. The bulk modulus of the material of the sphere is (Given density of sea water may be taken as 1.0 10 kg m ).

43:45 The metal cube of side 10 cm is subjected to a shearing stress of 10 N m . 4 2 The modulus of rigidity if the top of the cube is displaced by 0.05 cm with respect to its bottom is

50:11 A copper wire of length 2.4 m and a steel wire of length 1.6 m, both of diameter 3 mm, are connected end to end. When stretched by a load, the net elongation is found to be 0.7 mm. The load applied is (Y 1.2 10 N m , Y 2 10 N m )

Next Lecture Link : https://youtu.be/CrRhDaEx06w?si=XJB9cTjHcpivAujJ

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