Answer:
(b) To get m3 to slide, m1 must be increased, never decreased.
Explanation:
Lab experiments require attentiveness. If there is one thing missed or not taken seriously whole experiment could go wrong. In this case to slide m3 there should be more weight at m1. If the weight of m1 is lesser than m3 then the object will not slide. It will remain at the point where there is more weight. To slide an object there must be less frictional surface and more weight placed at the desired end point.
When the temperature lowers the plants can freeze and die. One way to prevent that is to cover the plants so they dont freeze
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:
The impulse on the object is 60Ns.
Explanation:
Impulse is defined as the product of the force applied on an object and the time at which it acts. It is also the change in the momentum of a body.
F = m a
F = m(
)
⇒ Ft = m(
- 
)
where: F is the dorce on the object, t is the time at which it acts, m is the mass of the object, is its initialvelocity and is the final velocity of the object.
Therefore,
impulse = Ft = m( - )
From the question, m = 3kg, = 0m/s and = 20m/s.
So that,
Impulse = 3 (20 - 0)
= 3(20)
= 60Ns
The impulse on the object is 60Ns.
