Question

132
Example 3 : A wooden toy rocket is in the
shape of a cone mounted on a cylinder, as
shown in Fig. 15.8. The height of the entire
rocket is 26 cm, while the height of the conical
part is 6 cm. The base of the conical portion
has a diameter of 5 cm, while the base
diameter of the cylindrical portion is 3 cm. If
the conical portion is to be painted orange
and the cylindrical portion yellow, find the
area of the rocket painted with each of these
colours. (Take Ti = 3.14)​

Answer 1

Answer:

Step-by-step explanation:

Area of the rocket, painted in orange:

CSA of cone = Pi*r*l = 3.14 * 5/2 * L cm

Here, we have to find length,

Lsquare = Rsquare + Hsquare

Lsquare = {(2.5*2.5) + (6*6)}square

= (6.25+36)square = (42.25)square

L = root(42.25) = 6.5 cm

So, 3.14*5/2*6.5 = 51.025cm square.

Area of the rocket, painted in yellow:

CSA of cylinder = 2*Pi*r*h = 2 * 3/2 * h

Here, we have to find height,

Since, the total height = 26cm and height of cone = 6cm

So, the height of cylinder = 26-6 = 20cm

So, 2*3.14*3/2*20 = 62.8cm square