Answer:
second-law efficiency = 62.42 %
Explanation:
given data
temperature T1 = 1200°C = 1473 K
temperature T2 = 20°C = 293 K
thermal efficiency η = 50 percent
solution
as we know that thermal efficiency of reversible heat engine between same temp reservoir
so here
efficiency ( reversible ) η1 = 1 -
............1
efficiency ( reversible ) η1 = 1 -
so efficiency ( reversible ) η1 = 0.801
so here second-law efficiency of this power plant is
second-law efficiency =
second-law efficiency =
second-law efficiency = 62.42 %
Answer:
1. James will attack by generating a random private key XD and a corresponding public key YD.
2. Jane transmit YA to another person called Alex.
3. James intercept YA and transmit YD to jane.
4. Jane receive YD and calculate K1
At this point james and jane thinks they share a secret key but instead james has a secret key k1 to Jane and k2 to alex.
5. Alex transmit another key XA to alex for example.
6. James intercept and calculate k2 and vice versa.
Answer:
a) P ≥ 22.164 Kips
b) Q = 5.4 Kips
Explanation:
GIven
W = 18 Kips
μ₁ = 0.30
μ₂ = 0.60
a) P = ?
We get F₁ and F₂ as follows:
F₁ = μ₁*W = 0.30*18 Kips = 5.4 Kips
F₂ = μ₂*Nef = 0.6*Nef
Then, we apply
∑Fy = 0 (+↑)
Nef*Cos 12º - F₂*Sin 12º = W
⇒ Nef*Cos 12º - (0.6*Nef)*Sin 12º = 18
⇒ Nef = 21.09 Kips
Wedge moves if
P ≥ F₁ + F₂*Cos 12º + Nef*Sin 12º
⇒ P ≥ 5.4 Kips + 0.6*21.09 Kips*Cos 12º + 21.09 Kips*Sin 12º
⇒ P ≥ 22.164 Kips
b) For the static equilibrium of base plate
Q = F₁ = 5.4 Kips
We can see the pic shown in order to understand the question.
Answer:
P > 142.5 N (→)
the motion sliding
Explanation:
Given
W = 959 N
μs = 0.3
If we apply
∑ Fy = 0 (+↑)
Ay + By = W
If Ay = By
2*By = W
By = W / 2
By = 950 N / 2
By = 475 N (↑)
Then we can get F (the force of friction) as follows
F = μs*N = μs*By
F = 0.3*475 N
F = 142.5 N (←)
we can apply
P - F > 0
P > 142.5 N (→)
the motion sliding