Answer: A) Cm = 2.232 s/mm² B) Time taken to solidify = 74.3 seconds Explanation: (A) Since a side is 50mm and all sides of a cube are equal, thus, Volume of the cube is;V = 50 x 50 x 50 = 125,000 mm³ There are 6 faces of the cube, thus Surface Area A = 6 x (50 x 50) = 15,000 mm² So, Volume/Area = (V/A) = 125,000/15,000 = 8.333 mm Cm is given by the formula; Cm =[Tts] /(V/A)² where Tts is time taken to solidify and it's 155 seconds in the question. Thus; Cm = 155/(8.333)²= 2.232 s/mm² (B) For;Cylindrical casting with D = 30 mm and L = 50 mm.; Volume of cylinder is; V = (πD²L) /4 So,V = (π x 30² x 50)/4 = 35,343mm³ Surface area of cylinder is; A = (2πD²)/4 + (πDL) Thus, A = ((π x 30²)/2) + (π x 30 x 50) = 6126 mm² Volume/Area is; V/A = 35,343/6126 = 5.77 mm Same alloy and mold type was hsed as in a above, thus, Cm is still 2.232 s/mm² Since Cm =[Tts] /(V/A)² Making Tts the subject, we have; Tts =Cm x (V/A)² Tts = 2.232 x (5.77)² = 74.3 seconds
Well it depends on how big the swimming pools are like one of those big ones or the kid ones also I’m thinking if it’s the little ones that’s it’d be like a 10 years but the big ones omg I have no clue
