Ex 9.2

Chapter 9 Class 7 Perimeter and Area
Serial order wise

### Transcript

Ex 9.2, 16 How many times a wheel of radius 28 cm must rotate to go 352 m? (ππππ π=22/7) In 1 rotation, wheel travels distance = Circumference Therefore, Number of rotations = (π«πππππππ πππππππππ)/(πͺππππππππππππ ππ πππππ) Circumference of wheel Radius of wheel = r = 28 cm Circumference of wheel = 2πr = 2 Γ ππ/π 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πππ π‘πππ£ππππ)/(πΆππππ’πππππππ ππ π€βπππ) β΄ Number of rotations = πππ/(π.ππ) = 352/176 Γ 100 = πππ/ππ Γ 100 = 88/44 Γ 100 = 2 Γ 100 = 200 β΄ Wheel rotates 200 times

#### Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.