The question is incomplete. The complete question is :
A viscoelastic polymer that can be assumed to obey the Boltzmann superposition principle is subjected to the following deformation cycle. At a time, t = 0, a tensile stress of 20 MPa is applied instantaneously and maintained for 100 s. The stress is then removed at a rate of 0.2 MPa s−1 until the polymer is unloaded. If the creep compliance of the material is given by:
J(t) = Jo (1 - exp (-t/to))
Where,
Jo= 3m^2/ GPA
to= 200s
Determine
a) the strain after 100's (before stress is reversed)
b) the residual strain when stress falls to zero.
Answer:
a)-60GPA
b) 0
Explanation:
Given t= 0,
σ = 20Mpa
Change in σ= 0.2Mpas^-1
For creep compliance material,
J(t) = Jo (1 - exp (-t/to))
J(t) = 3 (1 - exp (-0/100))= 3m^2/Gpa
a) t= 100s
E(t)= ΔσJ (t - Jo)
= 0.2 × 3 ( 100 - 200 )
= 0.6 (-100)
= - 60 GPA
Residual strain, σ= 0
E(t)= Jσ (Jo) ∫t (t - Jo) dt
3 × 0 × 200 ∫t (t - Jo) dt
E(t) = 0
Answer: d. evaporation and condensation
Water vapor is known as the main fuel that moves the hurricane. The evaporation will cause the water vapor to move upward carrying the latent heat of condensation. The vapor will cause condensation later. If both happen at a very high rate, the wind produced can become a hurricane.
The term “electric field” refers to the physical field that surrounds electrically charged particles and acts to either attract or repel all other charged particles in the field (also known as an E-field).
It can also refer to the physical field surrounding a system of charged particles. Electric fields are composed of electric charges and time-varying electric currents.
Both electric and magnetic fields are manifestations of the electromagnetic field, one of the four fundamental interactions (sometimes known as forces) of nature.
Electrical technology makes use of electric fields, which are significant in many branches of physics.
For instance, in atomic physics and chemistry, the electric field acts as an attractive force to hold atoms’ atomic nuclei and electrons together. It is also the force that causes atoms to chemically link together to form molecules.
To know more about electric field visit:
brainly.com/question/14811118
#SPJ4
The best thing to do is start out small. Do something that is in your comfort zone and get bigger each time. Before you know it, you will have gotten over your fear and it'll feel great :)
