


Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class
Ex 9.2
Ex 9.2, 1 (b) Important
Ex 9.2, 1 (c)
Ex 9.2, 2 (a) Important
Ex 9.2, 2 (b) Important
Ex 9.2, 2 (c)
Ex 9.2, 3
Ex 9.2, 4 Important
Ex 9.2, 5 Important
Ex 9.2, 6
Ex 9.2, 7 Important
Ex 9.2, 8
Ex 9.2, 9 Important
Ex 9.2, 10 Important
Ex 9.2, 11
Ex 9.2, 12 Important
Ex 9.2, 13 Important
Ex 9.2, 14
Ex 9.2, 15
Ex 9.2, 16 Important You are here
Ex 9.2, 17 Important
Last updated at July 4, 2023 by Teachoo
Ex 9.2, 16 How many times a wheel of radius 28 cm must rotate to go 352 m? (𝑇𝑎𝑘𝑒 𝜋=22/7) In 1 rotation, wheel travels distance = Circumference Therefore, Number of rotations = (𝑫𝒊𝒔𝒕𝒂𝒏𝒄𝒆 𝒕𝒓𝒂𝒗𝒆𝒍𝒍𝒆𝒅)/(𝑪𝒊𝒓𝒄𝒖𝒎𝒇𝒆𝒓𝒆𝒏𝒄𝒆 𝒐𝒇 𝒘𝒉𝒆𝒆𝒍) Circumference of wheel Radius of wheel = r = 28 cm Circumference of wheel = 2𝜋r = 2 × 𝟐𝟐/𝟕 × 28 = 2 × 22 × 4 = 44 × 4 = 176 cm = 176 × 1/100 m = 1.76 m Now Given, Distance travelled = 352 m Number of rotations = (𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑡𝑟𝑎𝑣𝑙𝑙𝑒𝑑)/(𝐶𝑖𝑟𝑐𝑢𝑚𝑓𝑟𝑒𝑛𝑐𝑒 𝑜𝑓 𝑤ℎ𝑒𝑒𝑙) ∴ Number of rotations = 𝟑𝟓𝟐/(𝟏.𝟕𝟔) = 352/176 × 100 = 𝟏𝟕𝟔/𝟖𝟖 × 100 = 88/44 × 100 = 2 × 100 = 200 ∴ Wheel rotates 200 times