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:
Positions in Hockey: 6 players for each team on the ice
1 Goalie – the player in the goal who tries to stop the puck from going in the net.
1 Center – plays in between the two wings and is usually the best passer on the team
2 Wings – offensive players who plays on both sides of the center. They are usually goal scorers
2 Defensemen – main job is to play defense and help defend the goal
Passing Cues
1. Stick blade faces target
2. Puck in center of blade
3. Transfer weight rear to front as you pass
4. Use wrist movement to drive the puck
5. Follow through at target
Receiving Cues:
1. athletic position
2. catch puck with middle of blade and control
3. slow the puck when it contacts the stick by giving with it
Explanation:
Answer:
Add an arrow above the symbol p to show it is a vector. Sometimes it is italicized in textbooks.
Explanation: