Banner 0
Banner 1
Banner 2
Banner 3
Banner 4
Banner 5
Banner 6
Banner 7
Banner 8
Banner 9

Q.

A boy is cycling such that the wheels of the cycle are making 140 revolutions per minute. The diameter of the wheel is 60 cm. Calculate the speed per hour with which the boy is cycling.


see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya

a

15.84 km/hr

b

440 km/hr

c

7.5 km/hr

d

60km/hr 

answer is A.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

JEE

NEET

NEET

Foundation JEE

Foundation JEE

Foundation NEET

Foundation NEET

CBSE

CBSE

Detailed Solution

It is given that a boy is cycling such that the wheels of the cycle are making 140 revolutions per minute. The diameter of the wheel is 60 cm.
We need to calculate the speed per hour with which the boy is cycling.
We know that the circumference of a circle with radius r units is 2πr units.
We also know that d=2r.
Therefore,
Circumference = πd units
In this case, the distance the boy covers is equal to the product of the circumference of the wheel and the number of revolutions.
Therefore,
Distance covered=Circumference×Number of revolutions
Distance covered=πd×140
Distance covered=227×60×140
Distance covered=26,400 cm
We know that 1km=1,00,000cm
26,400cm=0.264km
We know that 1 min= 160 hours.
We know that,
Speed=Distance coveredTime taken
Speed=0.264(160)
Speed=0.264×60
Speed=15.84km/hr
Therefore, the speed per hour with which the boy is cycling is 15.84km/hr.
Hence, the correct option is 1.
 
Watch 3-min video & get full concept clarity
score_test_img

courses

No courses found

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!

best study material, now at your finger tips!

  • promsvg

    live classes

  • promsvg

    progress tracking

  • promsvg

    24x7 mentored guidance

  • promsvg

    study plan analysis

download the app

gplay
mentor

Download the App

gplay
whats app icon
personalised 1:1 online tutoring