Ex 9.2, 16 - Chapter 9 Class 7 Perimeter and Area

Last updated at August 14, 2026 by

Ex 9.2, 16 - How many times a wheel of radius 28 cm must rotate - Ex 9.2

part 2 - Ex 9.2, 16 - Ex 9.2 - Serial order wise - Chapter 9 Class 7 Perimeter and Area
part 3 - Ex 9.2, 16 - Ex 9.2 - Serial order wise - Chapter 9 Class 7 Perimeter and Area

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Transcript

Ex 9.2, 16 How many times a wheel of radius 28 cm must rotate to go 352 m? (π‘‡π‘Žπ‘˜π‘’ πœ‹=22/7) In 1 rotation, wheel travels distance = Circumference Therefore, Number of rotations = (π‘«π’Šπ’”π’•π’‚π’π’„π’† 𝒕𝒓𝒂𝒗𝒆𝒍𝒍𝒆𝒅)/(π‘ͺπ’Šπ’“π’„π’–π’Žπ’‡π’†π’“π’†π’π’„π’† 𝒐𝒇 π’˜π’‰π’†π’†π’) Circumference of wheel Radius of wheel = r = 28 cm Circumference of wheel = 2πœ‹r = 2 Γ— 𝟐𝟐/πŸ• Γ— 28 = 2 Γ— 22 Γ— 4 = 44 Γ— 4 = 176 cm = 176 Γ— 1/100 m = 1.76 m Now Given, Distance travelled = 352 m Number of rotations = (π·π‘–π‘ π‘‘π‘Žπ‘›π‘π‘’ π‘‘π‘Ÿπ‘Žπ‘£π‘™π‘™π‘’π‘‘)/(πΆπ‘–π‘Ÿπ‘π‘’π‘šπ‘“π‘Ÿπ‘’π‘›π‘π‘’ π‘œπ‘“ π‘€β„Žπ‘’π‘’π‘™) ∴ Number of rotations = πŸ‘πŸ“πŸ/(𝟏.πŸ•πŸ”) = 352/176 Γ— 100 = πŸπŸ•πŸ”/πŸ–πŸ– Γ— 100 = 88/44 Γ— 100 = 2 Γ— 100 = 200 ∴ Wheel rotates 200 times

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