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:
a; P = 15.25 kips
b) Q = 5.4 kips
Explanation:
To understand scenerio, see attached image also.
Consider the forces acting on the system, F1 is the force acting against the direction of P, F2 acting in the along direction of P, N is at angle 12 degrees
Calculating F1, we have;
F1 = µ x 18 = 0.30 x 18 = 5.4 kips
F2 = = µ x N = 0.3N
To be in static condition, sum of forces would be equal to 0
18 = N cos 12 – F2 sin 12
Putting value of F2 and solving above equation for N;
N x 0.915 = 18
N = 19.65 kips
Now the wedge will move if, P > ( F1 + F2 cos 12 + N sin 12)
Putting the values;
P >= 15.25 kips
The corresponding force Q will be equal to F1 = 5.4 kips
Answer:
The sum of all currents entering a junction is 0
Explanation:
Current cannot disappear, so the currents leaving a junction have to equal the currents entering a junction. If you would give the currents leaving the junction an opposite sign (e.g., negative) it implies that the sum of all these currents is exactly 0.
