A wheel makes 2000 revolutions in covering a distance 7.92 km. The Diameter of wheel is....

M4maths Previous Puzzles

03 Apr 2013 wheel

A wheel makes 2000 revolutions in covering a distance 7.92 km. The Diameter of wheel is....

OPtion

1) .63 m
2) 3.96 m
3) .126 km
4) 12.6 m
5) 1.26 m
6) 1.62 m
7) 2.52 m
8) 1.26 km
9) 2 m
10) None of these

Solution

2000 revolutions = 7.92 km distance cover
1 revolution = 7.92/2000 km
= (7.92*1000)/2000 m
1 revolution = circumference of wheel
circumference of wheel = 792/200 m
therefore 2r = (792*7)/(200*22)
solve
option 5

Correct Option: 5 Best Solution (21)

Mukesh Kr Singh   11 years AGO

1 revolution=perimeter of wheel
p=7920/2000=3.96m
pi*D=3.96
D=1.26

Like? Yes (4) | No (1)  

AVINASH KUMAR   11 years AGO

200*pi*d=7.92*1000m
d=1.26 m

Like? Yes (3) | No (1)  

Rashmi Mehta   11 years AGO

2000*2*pi*r=7.92*1000
diameter=2*r=(7.92*1000)/(3.14*2000)=1.26 m

Like? Yes (2) | No   

D.Jagruthi   11 years AGO

circumfernce of the circle =2*pi*r*n
where n=no. of revolutions
so,2*(22/7)*r*2000=7920
=> r=0.63
=>diameter=2*0.63=1.26m

Like? Yes (2) | No (1)  

PALLAVI PRATAP   11 years AGO

in 1 revolution, distance covered=circumference=2*3.14*radius
therefore,distance covered in 2000 revolutions=2000*2*3.14*radius=7.92km
radius=0.00063km
diameter=2*radius=0.00126km=0.00126*1000m= 1.26m

Like? Yes (1) | No   

anil kumar   11 years AGO

2000*2*3.14*r=7.92*1000
r=.63
d=1.26

Like? Yes (1) | No   

Kalpesh   11 years AGO

The total distance travelled is 7.92 km = 7920 m
No. of revolutions = 2000
Now
Distance travelled in 1 revolution = 2 * 22/7 * R
=> Distance travelled in 2000 revolutions = 2 * 22/7 * R * 2000
=>1000 * 2 * 22/7 * R = 7920
=> R = 7920 * 7/2000/ 2 / 22
=> = .63m
Thus , radius of wheel = .63 m
and , diameter of wheel = 2 * R
= 2 * .63
= 1.26 m

Like? Yes (1) | No (1)  

Devendra Marghade   11 years AGO

One revolution covers the distance(in mt.)=7920/2000
2Pi*R=Pi*D=7920/2000
So D=7920*7/(2000*22)=1.26 m

Like? Yes (1) | No (1)  

Balakrishnan M   11 years AGO

A wheel makes 2000 revolutions in covering a distance 7.92 km.
It's covering for 1 revolution is = 7920/2000
= 3.96m
Perimeter of the wheel is 2*pi*r=3.96m
r=3.96*(7/22)*(1/2)
r=0.63m
diameter=2*0.63=1.26m

Like? Yes (1) | No (1)  

Vinay Sipani    11 years AGO

1 revolution => distance travelled = pi x D
2000 revolution => 2000 x pi x D = 7920 m
=> D = 1.26 m

Like? Yes (1) | No (1)  

Girish Damodar Ballampalli   11 years AGO

As we get 2r=7920/(2000*3.14)
Therfore, diameter=1.26m

Like? Yes (1) | No (1)  

Nitesh Kanojiya   11 years AGO

perimeter of wheel * 2000 = 7.92km
πd * 2000 = 7920m
solve for d
d=1.26m

Like? Yes (1) | No (1)  

devendra kumar gond   11 years AGO

2R=(7.92*1000)/2000PIE

Like? Yes (1) | No (1)  

anjul meid   11 years AGO

7920/(2000*3.14)=1.26m

Like? Yes (1) | No (1)  

srinivasulareddy   11 years AGO

2000*2*22/7*r=7920m
2r=1.26m

Like? Yes (1) | No (1)  

Sanjeewani Indurkar   11 years AGO

2000*2*pi*r=7.92km
2r=7.92/(2000*pi)
therefore, diameter=1.26m

Like? Yes (1) | No (1)  

Balakumaran N.A   11 years AGO

The total distance travelled is 7.92 km = 7920 m
No. of revolutions = 2000
Now
Distance travelled in 1 revolution = 2 * 22/7 * R
=> Distance travelled in 2000 revolutions = 2 * 22/7 * R * 2000
=> 2000 * 2 * 22/7 * R = 7920
=> R = 7920 * 7/2000 * 2 * 22
=> = 0.63m
Thus , radius of wheel = 0.63 m
and , diameter of wheel = 2 * R
= 2 * 0.63
= 1.26 m

Like? Yes (1) | No (1)  

Rachita Dash   11 years AGO

1 revolution = circumferrence of the circle
so
2*3.14*r*2000=7.92*1000
=>r=0.63
=>diameter=1.26

Like? Yes (1) | No (1)  

shubhangi   11 years AGO

circumference=dist./revaluation

2*pi*r=7.92*100000cm/2000

r=7.92*100000cm/2000*2*3.14

r=63.05
diameter=2r=2*63.05
=126.11cm
=1.26m

Like? Yes (1) | No (1)  

MANISH KUMAR   11 years AGO

2pi*r*2000=7.92*1000
2r=1.26m

Like? Yes (1) | No (1)  

Komal Rachna   11 years AGO

7920m distance is covered in 2000 revolutions.so 7920/2000=(792/200)m distance is travelled in one revolution.It means circumference of circle is 792/200..2*pi*r=792/200.so 2r=63/50+(1.26)m...so 1.26 is the answer

Like? Yes (1) | No (1)