Question

8. From a solid cylinder whose height is 2.4 cm and diameter 1.4 cm, a conical cavity of the
same height and same diameter is hollowed out. Find the total surface area of the
remaining solid to the nearest cm.
Is this not the solution?​

Answer 1

Answer:

Given:

Height (h) of the conical part = Height (h) of the cylindrical part =2.4 cm

Diameter of the cylindrical part =1.4 cm

Radius =

2

Diameter

Radius(r) of the cylindrical part =0.7 cm

Slant height (l) of conical part =

r

2

+h

2

=

0.7

2

+2.4

2

=

0.49+5.76

=

6.25

=2.5

Total surface area of the remaining solid = CSA of cylindrical part + CSA of conical part + Area of cylindrical base

=2πrh+πrl+πr

2

=2×

7

22

×0.7×2.4+

7

22

×0.7×2.5+

7

22

×0.7×0.7

=4.4×2.4+2.2×2.+2.2×0.7

=10.56+5.50+1.54=17.60 cm

2

The total surface area of the remaining solid to the nearest cm

2

is 18 cm

2

Step-by-step explanation:

I hope it help you