Question

How much iron is needed to make a road roller of length 90cm and diameter of 1.4cm?Also find the curved surface area of the roller​

Answer 1

Answer:

(i) Here, l = 1.5 m, b = 1.25 m                                  ∵ It is open from the top.                 ∵ Its surface area = [Lateral surface area] + [Base area]                 = [2(l + b)h] + [l × b]                 = [2(1.50 + 1.25)0.65 m2] + [1.50 × 1.25 m2]                 = [2 × 2.75 × 0.65 m2] + [1.875 m2]                 = 3.575 m2 + 1.875 m2 = 5.45 m2                 ∵ The total surface area of the box = 5.45 m2                 ∴ Area of the sheet required for making the box = 5.45 m2           (ii) Rate of sheet = Rs. 20 per m2                 Cost of 5.45 m2 = Rs. 20 × 5.45                                  ⇒ Cost of the required sheet = Rs.109

Step-by-step explanation:

Answer 2

Step-by-step explanation: = 22/7 x 1.4 x 1.4

= 61.6 cm^3