A solid wooden toy is in the from of a hemisphere surmounted by a cone of same radius.the radius of hemisphere is 3.5 cm and the total wood used in the making of toy is 166 5/6 cm3 find the height of the toy also find the cost of painting the hemisphere part of the toy at the rate of Rs.10 per cm2 [Use π = 22/7]
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3
Answer:
Answer
r = radius of hemisphere and cone = 3.5 cm ; h = height of cone
Volume, Vtotal=Vcone+Vhemisphere=31πr2h+32πr3 =166.83cm3
⇒πr2(h+2r)=500.5cm3
⇒h+2(3.5)=π×3.52500.5
Hence h=13−7=6cm
Height of toy =h+r=6+3.5=9.5cm
Surface area of hemisphere =2π(3.5)2=77cm2
Cost =Rs.770
Answered by
3
Answer:
r = radius of hemisphere and cone = 3.5 cm ; h = height of cone
Volume, V
total
=V
cone
+V
hemisphere
=
3
1
πr
2
h+
3
2
πr
3
=166.83cm
3
⇒πr
2
(h+2r)=500.5cm
3
⇒h+2(3.5)=
π×3.5
2
500.5
Hence h=13−7=6cm
Height of toy =h+r=6+3.5=9.5cm
Surface area of hemisphere =2π(3.5)
2
=77cm
2
Cost =Rs.770
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