It is known that there are some disadvantages in the casting of metal materials if the casting rate is high. Contrary to this si
tuation, are there any disadvantages to using very slow casting rates in the production of metals by casting method? If so, explain what these are?
1 answer:
Answer:
The disadvantages of slow casting rate in the production of metal by casting are:
1. Solidification of metal may start even before the mould is completely filled which may produce defects like misruns and shrinkage capacity as shown in the attachment.
So slow casting rate will produce incomplete and partial casting
2. Slow casting rate will produce casting which have a coarse grain structure which in turn affects the strength of the casting adversely.
3.It causes higher production time for production of casting which in turn increase high labour cost per casting.
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The image is missing, so i have attached it.
Answer:
A) P = 65.11 KN
B) Q = 30 KN
Explanation:
We are given;
The end reaction of the beam; F = 100KN
Coefficient of static friction between two steel surfaces;μ_ss = 0.3
Coefficient of static friction between steel and concrete;μ_sc = 0.6
So, F1 = μ_ss•F =0.3 x 100 = 30 KN
F2 = μ_ss•N_EF = 0.3N_EF
From the screen shot, we see that the angle is 12°
Sum of forces in the Y-direction gives;
F2•sin12 - N_EF•cos12 + 100 = 0
Rearranging gives;
N_EF•cos12 - F2•sin12 = 100
Let's put 0.3N_EF for F2 to give;
N_EF•cos12 - 0.3N_EF•sin12 = 100
Thus;
N_EF(0.9158) - 0.1247 = 100
N_EF(0.9781) = 100 + 0.1247
N_EF = 100.1247/0.9158
N_EF = 109.33 KN
Thus, F2 = 0.3N_EF = 0.3 x 109.33 = 32.8 KN
Wedge will move if;
P = (F1 + F2cos12 + N_EFsin12)
Thus;
P = 10 + (32.8 x 0.9781) + (109.33 x 0.2079)
P ≥ 65.11 KN
B) For static equilibrium, Q = F1
Thus, Q = 30 KN
