Question

Students of Class X of a school are asked to do an activity
to understand surface area and volume of solid figures.
They have taken a wooden article which is made by
scooping out a hemisphere from each end of a solid
cylinder, as shown in the figure. If the height of the
cylinder is 20 cm and its base radius is 7 cm.
Give answer to his questions by considering the given
information and the figure.
(a) Find the curved surface area of each hemisphere.
(i) 400 cm2 (ii) 305 cm2
(iii) 308 cm2
(iv) 406 cm2
(b) Write the formula to find the volume of two hemisphere with
radius r?
.3
πη
(1) ar r3 (ii)
(iii) ter3
(iv) š ter3
(c) Write the formula to find the volume of cylinder.
(1) rah
(ii) arah
(iii) r3
(iv) 5nr 3
(d) What is total volume of remaining part of solid?
(i) 1642.67 cm3
(ii) 2000.00 cm3 (iii) 1932.15 cm3 (iv) 1315.17 cm3
(e) Find the total surface area of the article.
(i) 1450 cm?
(ii) 1496 cm2 (iii) 1552 cm2 (iv) 1537 cm​

Answer 1

Answer:

We have

Height of cylinder= 10cm

radius of base= 3.5cm

Total surface area of the article =Curved surface area of the cylinder +2 surface area of a hemisphere

=2πrh+2(2πr

2

)

=2πr(h+2r)

=2×

7

22

×3.5(10+2×3.5)cm

2

=374cm

2