Question

A metaalic cylinder is 15cm high &the diameter of its base is 14cm.it iselted &recasted into another cylinder with radius 4cm . find height &c.s.a , t.s.a of new cylinder

Answer 1

given,
height of the first cylinder =15 cm
diameter of the first cylinder = 14 cm
radius of the first cylinder = diameter / 2
r=14/2=7
volume of the first cylinder= volume of the second cylinder
πr1²h1 =πr2²h2
r1²h1=r2²h2
7²×15=4²h2
h2 = 7×7×15/4²
h2=7×7×15/4×4
h2=45.9375 cm
h2=46 cm
CSA=2πrh
=2×22/7×4×46
=2×22×4×46/7
=1156.5 cm²
TSA=2πr(r+h)
=2×22/7×4(4+46)
=2×22/7×4×50
=2×22×4×50/7
=1257.14 cm²