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The mechanical properties of materials define how materials behave when subjected to external forces known as loads. There is a measure of the strength and durability of the material in service, which is important in the design of tools, machines, and structures.
Mechanical properties can also be used to help specify and identify metals. Strength, hardness, ductility, brittleness, toughness, stiffness, and impact resistance are the most common properties considered.
QUESTION 1: If a compressed spring is dissolved in acid, what happened to the elastic potential energy of the spring?
SOLUTION 1: When a compressed spring dissolves in acid, the acid molecules leave the spring’s sold lattice faster than an uncompressed spring. This raises the kinetic energy of the solution. The temperature of the acid rises as a result. However, because the mechanical energy content of the spring is less than its chemical energy content, the temperature increase will be very small.
QUESTION 2: When some wax is rubbed on a cloth, it becomes waterproof. Explain.
SOLUTION 2: When the angle of contact between a liquid and a surface is small or zero, the liquid wets the surface. When cloth comes into contact with water, it produces capillary action due to its fibrous nature. As a result, clothing has very small contact angles with water. Water does not wet the cloth when the wax is rubbed over it because wax has a high contact angle with water.
QUESTION 3: When a glass capillary tube is dipped at one end in water, the water rises in the tube. The gravitational potential energy is thus increased. Is it a violation of the conservation of energy?
SOLUTION 3: No, it does not violate the principle of energy conservation.
Because of the attraction between glass and water, the liquid rises in the tube. When water and glass are not in contact, however, there is potential energy in the system. When they come into contact, the potential energy is converted first into kinetic energy, which causes the liquid to rush upwards in the tube, and then into gravitational potential energy. As a result, no energy is generated during the process.
QUESTION 4: Frictional force between solids operates even when they do not move with respect to each other. Do we have a viscous force acting between two layers even if there is no relative motion?
SOLUTION 4: No, there are no viscous forces in a liquid at rest.
Viscous forces oppose relative motion between liquid layers. These layers do not exist in a resting liquid. As a result, it is obvious that viscous forces do not exist in a static liquid.
FAQs:
How do you determine the mechanical properties of metals?
Metal mechanical properties are determined by the metal's range of usefulness and establish the service that is expected. Mechanical properties can also be used to help specify and identify metals.
How would I address HC Verma's questions?
Begin from the principal part. Try not to bounce or continue in an irregular way. Peruse the whole section prior to endeavouring to tackle the issues. Peruse at your own speed and ensure you got the ideas.
