Check sibling questions

Ex 13.2, 4 - Chapter 13 Class 9 Surface Areas and Volumes (Term 2)

Last updated at May 29, 2018 by

Ex 13.2, 4 - The diameter of roller is 84 cm and its length - Area Of Cylinder

Β 

This video is only available for Teachoo black users

Subscribe Now

Introducing your new favourite teacher - Teachoo Black, at only β‚Ή83 per month

Join Teachoo Black

Transcript

Ex 13.2, 4 The diameter of a roller is 84 cm and its length is 120 cm. It takes 500 complete revolutions to move once over to level a playground. Find the area of the playground in m2? [π΄π‘ π‘ π‘’π‘šπ‘’ πœ‹= 22/7] Roller is of form cylinder Radius = π·π‘–π‘Žπ‘šπ‘’π‘‘π‘’π‘Ÿ/2 = 84/2 = 42 cm Area of roller = Curved surface of cylinder = 2Ο€rh = (2Γ—22/7Γ—42Γ—120) cm2 = 31680 cm2 Area of 1 revolution = Area of roller = 31680 cm2 Area of 500 revolution = 500 Γ— 31680 cm2 Area of playground = 15840000 cm2 = 15840000 Γ—1/(100 ) Γ—1/(100 )m2 = 1584 m2

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.