ALL MECHANICAL ENGINEERING
TERMS QUESTIONS AND VERIFIED
ANSWERS|100% CORRECT|GRADE A+
Equations of motion - ANSWER v=u+at
v²-u²=2as
s=ut+½at²
Density or Mass density - ANSWER Density or mass density of a fluid is defined as the ratio of the mass
of the fluid to its volume.Unit-SI= kg/m3
The value of density of water is 1000 kg/m3
Buoyancy - ANSWER When a body is immersed in a fluid, an upward force is exerted by the fluid on the
body. This upward force is equal to the weight of the fluid displaced by the body and is called as force of
buoyancy or simply buoyancy.
Bernoulli's equation - ANSWER P+0.5*(density)*v^2) + (density)*gravity*height = constant
P=absolute pressure of the fluid
density=density of the fluid
v=velocity of the fluid
g=acceleration due to gravity
h=height of the fluid relative to some reference height
For a system in which you have constant height (when you look at two distinc points along the fluid
flow), then Bernoulli's equation says that increased velocity means decreased pressure, and decreased
velocity means increased pressure.
Strength - ANSWER The strength of a material is its ability to sustain loads without undue distortion,
collapse or rupture. A material should have adequate strength when subjected to tension, compression,
shear, bending or torsion as per the intended use. For example, a beam of a building should have a
proper bending strength, a column should have adequate compressive strength, a shaft of an automobile
should have proper torsional strength. The maximum stress that any material will withstand is called
ultimate strength or tenacity.
, ELASTICITY - ANSWER it is property of material by virtue of which It regains its original size and shape
after deformation when the loads causing deformation are removed.
Plasticity - ANSWER Lack of elasticity is called plasticity
Ductility - ANSWER It is the property of a material to undergo a considerable deformation under tension
before rupture. A body possessing ductility can be reduced from large sections to thinner and thinner
sections i. e. it can be drawn into wires. This is tensile quality of a material.
Brittleness - ANSWER Lack of ductility is called brittleness. The brittleness of a material is the property of
breaking, fracturing or shattering without prior warning or without much permanent distortion under
load. There are many materials which shatter before much deformation takes place. e. g. cast iron, glass,
concrete, stone, etc. These materials are suitable for resisting compressive loads but usually less suitable
for resisting tensile and Impact load. The compression test is generally performed for testing the
brittleness of a material Brittleness is a compressive quality of a material.
Malleability - ANSWER It is the property of a material by virtue of which it gets permanently deformed
by compression without rupture. It is the ability of a material to be rolled or beaten up into thin sheets
without cracking by rolling and hammering. This is also a compressive quality of a material. Gold is the
most malleable of all metals.
Impact Strength - ANSWER Energy required to fracture with a sudden force.
endurance limit - ANSWER phenomenon of failure of a material under fluctuating or repeated loading is
called fatigue or endurance. Fatigue fracture is progressive, and starts as minute cracks at the centres of
stress concentration within the material or on the surface. These cracks go on extending more and more
under the action of the fluctuating stresses causing the failure.
The maximum stress that a material can sustain without failure for a specific large number of cycles of
stresses is known as its fatigue value or endurance limit.
Stiffness - ANSWER The ability of a material to resist elastic deformation is called stiffness.
Mathematically it is the load required to produce unit deformation. A material which deforms by a lesser
amount under a given load possesses 'a high degree of stiffness. For identical cross sections, the stiffness
is proportional to the modulus of elasticity.
TERMS QUESTIONS AND VERIFIED
ANSWERS|100% CORRECT|GRADE A+
Equations of motion - ANSWER v=u+at
v²-u²=2as
s=ut+½at²
Density or Mass density - ANSWER Density or mass density of a fluid is defined as the ratio of the mass
of the fluid to its volume.Unit-SI= kg/m3
The value of density of water is 1000 kg/m3
Buoyancy - ANSWER When a body is immersed in a fluid, an upward force is exerted by the fluid on the
body. This upward force is equal to the weight of the fluid displaced by the body and is called as force of
buoyancy or simply buoyancy.
Bernoulli's equation - ANSWER P+0.5*(density)*v^2) + (density)*gravity*height = constant
P=absolute pressure of the fluid
density=density of the fluid
v=velocity of the fluid
g=acceleration due to gravity
h=height of the fluid relative to some reference height
For a system in which you have constant height (when you look at two distinc points along the fluid
flow), then Bernoulli's equation says that increased velocity means decreased pressure, and decreased
velocity means increased pressure.
Strength - ANSWER The strength of a material is its ability to sustain loads without undue distortion,
collapse or rupture. A material should have adequate strength when subjected to tension, compression,
shear, bending or torsion as per the intended use. For example, a beam of a building should have a
proper bending strength, a column should have adequate compressive strength, a shaft of an automobile
should have proper torsional strength. The maximum stress that any material will withstand is called
ultimate strength or tenacity.
, ELASTICITY - ANSWER it is property of material by virtue of which It regains its original size and shape
after deformation when the loads causing deformation are removed.
Plasticity - ANSWER Lack of elasticity is called plasticity
Ductility - ANSWER It is the property of a material to undergo a considerable deformation under tension
before rupture. A body possessing ductility can be reduced from large sections to thinner and thinner
sections i. e. it can be drawn into wires. This is tensile quality of a material.
Brittleness - ANSWER Lack of ductility is called brittleness. The brittleness of a material is the property of
breaking, fracturing or shattering without prior warning or without much permanent distortion under
load. There are many materials which shatter before much deformation takes place. e. g. cast iron, glass,
concrete, stone, etc. These materials are suitable for resisting compressive loads but usually less suitable
for resisting tensile and Impact load. The compression test is generally performed for testing the
brittleness of a material Brittleness is a compressive quality of a material.
Malleability - ANSWER It is the property of a material by virtue of which it gets permanently deformed
by compression without rupture. It is the ability of a material to be rolled or beaten up into thin sheets
without cracking by rolling and hammering. This is also a compressive quality of a material. Gold is the
most malleable of all metals.
Impact Strength - ANSWER Energy required to fracture with a sudden force.
endurance limit - ANSWER phenomenon of failure of a material under fluctuating or repeated loading is
called fatigue or endurance. Fatigue fracture is progressive, and starts as minute cracks at the centres of
stress concentration within the material or on the surface. These cracks go on extending more and more
under the action of the fluctuating stresses causing the failure.
The maximum stress that a material can sustain without failure for a specific large number of cycles of
stresses is known as its fatigue value or endurance limit.
Stiffness - ANSWER The ability of a material to resist elastic deformation is called stiffness.
Mathematically it is the load required to produce unit deformation. A material which deforms by a lesser
amount under a given load possesses 'a high degree of stiffness. For identical cross sections, the stiffness
is proportional to the modulus of elasticity.
