#1**+1 **

(3a) Plaster required =

(1/3) (area of base ) ( height) =

(1/3) (15^2) ( 12) =

4 * 225 =

900 cm^3

(3b) The scale factor of the prop is 3 times that of the model

So....the volume of the prop =

Volume of model * (scale factor)^3 =

900 * (3)^3 =

900 * 27 =

24,300 cm^3

(3c) The volume of the prop is 27 times that of the model = (scale factor)^3 = 3^3 = 27

CPhill Feb 12, 2019