Question

plz answer with explaination​

Answer 1

Solution :

• 1st cylindrical shape :

Height = 49 cm

Diameter of base = 16 cm

Radius of base = 16/2 cm = 8 cm

∴ volume (V₁) = π * 8² * 49 cm³

• 2nd cylindrical shape :

Height = 35 cm

Diameter of base = 14 cm

Radius of base = 14/2 cm = 7 cm

∴ volume (V₂) = π * 7² * 35 cm²

• Final cylindrical shape :

Height = 56 cm

Radius of base = r cm (say)

∴ volume (V) = π * radius² * 56

ATQ,

V = V₁ + V₂

or, π * r² * 56 = (π * 8² * 49) + (π * 7² * 35)

or, 56 r² = (8² * 49) + (7² * 35)

or, 8 r² = (8² * 7) + (7² * 5)

or, 8 r² = 448 + 245

or, 8 r² = 693

or, r² = 86.625

or, r ≈ 9.31

∴ the radius of the base of the new cylindrical shape is 9.31 cm and thus its diameter is (2 * 9.31) cm, i.e. 18.62 cm