A cylindrical rod of height 10 m and radius 7m is melted into 7 identical cylindrical pistons of radius 14m and height 514m
Then,
(1) The volume of the cylindrical rod is equal to the sum of the volume of all 7 pistons .
(2) The total surface area of the cylindrical rod is equal to the sum of total surface area of the cylindrical piston.
Only I is correct
Volume of the cylindrical rod = πr2h
= 227×7×7×10
= 1540m3
Volume of one cylindrical piston = πr2h
=
22/7×/142×5/14
= 220 m3
Volume of 7 cylindrical pistons = 7 ×220
=1540m3
= Volume of cylindrical rod.
So, statement 1 is correct.
Now,
Total surface area of cylindrical rod = 2πrh+2πr2
2×22/7×/7×10+2×227×7×7
= 440+308
=748m2
Total Surface area of cylindrical piston = 2πrh+2πr2
2×227×/14×5/14+2×227×14×14
=2207+86247
= 88447m2
Total surface area of 7 cylindrical piston
= 7×88447
= 8844m2
So, statement II is wrong.