Respuesta :
Answer:
Diameter of riser =6.02 mm
Explanation:
Given that
Dimensions of rectangular plate is 200mm x 100mm x 20mm.
Volume of rectangle V= 200 x 100 x 20 [tex]mm^3[/tex]
Surface area of rectangle A
A=2(200 x 100+100 x 20 +20 x 200)[tex]mm^2[/tex]
So V/A=7.69
We know that
Solidification times given as
[tex]t=K\left(\dfrac{V}{A}\right)^2[/tex] -----1
Lets take diameter of riser is d
Given that riser is in spherical shape so V/A=d/6
And
Time for solidification of rectangle is 3.5 min then time for solidificartion of riser is 4.2 min.
Lets take [tex]\dfrac{V}{A}=M[/tex]
[tex]\dfrac{M_{rac}}{M_{riser}}=\dfrac{7.69}{\dfrac{d}{6}}[/tex]
Now from equation 1
[tex]\dfrac{3.5}{4.2}=\left(\dfrac{7.69}{\dfrac{d}{6}}\right)^2[/tex]
So by solving this d=6.02 mm
So the diameter of riser is 6.02 mm.
