What is elasticity?
Elasticity is the ability of a material to return to its original shape after being deformed when the deforming force is removed.
What is Hooke’s Law?
Hooke's Law states that the extension of an elastic
object is
directly proportional to the force applied, provided
the elastic
limit is not exceeded:
$$ F = kx $$
What is the spring constant?
The spring constant \( k \) is a measure of the
stiffness of a
spring. It is defined by:
$$ k = \frac{F}{x}
$$
What is the limit of proportionality?
The limit of proportionality is the point beyond which extension is no longer proportional to force. Hooke’s Law no longer applies past this point.
What is the elastic limit?
The elastic limit is the maximum force a material can withstand and still return to its original shape. Beyond this, permanent deformation occurs.
What is tensile stress?
Tensile stress is the force per unit cross-sectional
area:
$$
\text{Tensile stress} = \frac{F}{A} $$
What is tensile strain?
Tensile strain is the ratio of extension to original
length:
$$ \text{Tensile strain} = \frac{\Delta
L}{L} $$
What is Young’s Modulus?
Young’s Modulus is the ratio of tensile stress to
tensile
strain:
$$ E =
\frac{\text{Stress}}{\text{Strain}} = \frac{F
L}{A \Delta L} $$
What does a high Young’s modulus indicate?
A high Young’s modulus means the material is stiff—it requires a large stress to produce a small strain.
What is meant by plastic deformation?
Plastic deformation is a permanent change in shape that occurs when a material is stretched beyond its elastic limit.
What is the work done by a spring?
The work done in stretching a spring is:
$$ W =
\frac{1}{2} F
x = \frac{1}{2} k x^2 $$
What is the energy stored in a stretched spring?
The elastic potential energy stored is:
$$ E =
\frac{1}{2} k
x^2 $$
What does the area under a force-extension graph represent?
The area under a force-extension graph represents the work done or energy stored in the spring.
What is meant by breaking stress?
Breaking stress is the maximum tensile stress a material can withstand before breaking.
What is ultimate tensile stress (UTS)?
UTS is the maximum stress a material can endure before it begins to break or weaken.
What is elastic deformation?
Elastic deformation occurs when a material returns to its original shape after the force is removed.
What is a spring balance?
A spring balance is a device used to measure force or weight using the extension of a spring.
How does a spring balance work?
It works on Hooke’s law: the extension of the spring is directly proportional to the force applied to it, within the elastic limit.
What unit does a spring balance measure in?
A spring balance typically measures force in newtons (N).
What are two uses of a spring balance in experiments?
1. Measuring the weight of objects.
2. Determining
the force
of friction or tension in a setup.
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