1. The ratio between curved surface area and total surface area of a right angle circular cylinder is 2:3 find ratio between height and radius of cylinder.

2 . A shotput is a metallic sphere of radius 4.2 cm. If density of metal is 10 gram per cm sq , find mass of shotput.

3.
A tailor has a piece of canvas whose area is 552 M sq.he uses it to make a conical tent with base radius 7cm.Assuming that all stitching margin and wastage incurred while cutting,amounts
to approximately 2 M sq. Find volume of tent that can be made with it (Also write values).

4. A conical vessel with radius 20 cm and height 30 cm is full of water. The water of the vessel is transferred to cylindrical vessel of radius 8 cm. Find up to what height will the cylindrical vessel fill.

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Answers

2015-01-10T11:45:18+05:30
1.curved surface area of a right angle cylinder =22 \pi rh
total surface area of a right angular cylinder= \pi r(h+r)
csa/tsa=2/3
pi x r on both the sides get cancelled
2h/h+r=2/3
6h=2h+2r
3h=2r
h/r=3/2
2.Area of sphere=4 x pi x r x r
4 x 22/7*4.2*4.2
221.76sq cm
mass=221.76*10=2217.6g
4.volume of cone=1/3*pi*r²*h
volume of cylinder=pi*r²*h
ATQ
volume of cone =volume of cylinder        
where the height of cylinder is not given
1/3*pi*r²*h=pi*r²*h
pi on both ides get cancelled
1/3*20*20*30=64*h
4000=64*h
4000/64=h
62.5=h
3.csa of conical tent =552m²
but 2m² is cut after stiching so the remaining area is 550m²
csa of cone =pi*r*l
550=22/7*7*h
550*7/22*7=h
25m=h

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