A semicircular sheet of metal of diameter 28 cm is bent into an open conical cup. The capacity of the cup (Take π=22\7) is

Explanation:

In this question just cut the semicircular paper and told it to form cone

⇒ Circumference of cone = circumference of semi circle

⇒2×π×(14)\2=2πr\2

⇒2πr=π×14

r=7cm

Slant height, (l) of cone = radius of semicircular plate

l=14cm

h^2=l^2−r^2

=14^2−7^2=196−49

=147

h=√147=7√3

Volume of cone =1\3×22\7×7×7×7√3

=622.36cm^3