If every side of a cube of volume V is doubled, its volume becomes kV, then the value of k is....

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19 Feb 2013 cube

If every side of a cube of volume V is doubled, its volume becomes kV, then the value of k is....

OPtion

1) V^3
2) k^3
3) V
4) k
5) 2k
6) 4
7) 6
8) 8
9) 8V
10) None of these

Solution

Cube Volume = side^3 (Cube has equal side)
By the given condition
let side be = a
when its doubled then side will 2a
Then V = 8a^3
but V = ka^3
8a^3 = ka^3
8=k
therefor k=8.......
option 8

Correct Option: 8 Best Solution (25)

Dr.Dipin Singh   11 years AGO

If x is the initial side of cube, then
x^3= V
when every side of a cube of volume V is doubled,
every side becomes 2x.
then new volume = (2x)^3 = 8x^3=8V=kV

then k=8 .. option 8

Like? Yes (5) | No (2)  

ArunKumar   11 years AGO

v= a^3
kv = (2a) ^3
= 8 a^3
= 8 v
k = 8

Like? Yes (4) | No (3)  

RAHUL RAJ   11 years AGO

let side of cube is a
volume=a^3=V
NEW VOLUME=8a^3=8V=kV
hence k=8

Like? Yes (1) | No   

Vidya Sagar   11 years AGO

If side is s, the volume is V i.e., V = s^3
If the side is 2s then the volume is 8s^3
That means, kV = 8s^3
Therefore, k = 8

Like? Yes (1) | No   

push   11 years AGO

2v^3=8v^3=kkv^3

; k=8

Like? Yes (1) | No   

kalaiarasan   11 years AGO

volume of cube v=a^3 => a*a*a
then doubled=> 8a^3 => 2a*2a*2a
volume => 8a^3=kv ------ equation
substitute v=a^3 in equation
8a^3=k.a^3
cancel a^3 both sides
so,k=8

Like? Yes (3) | No (2)  

sc mandota   11 years AGO

bcoz side^3=v
then (2*side)^3=8v

Like? Yes (3) | No (3)  

balram meena   11 years AGO

when side incereased by 2 time then volume increased by 8 times

Like? Yes (3) | No (3)  

Abhijeet Kumar   11 years AGO

volume of cube=L*B*H
L=B=H=2V
volume= (2V)^3
= 8V
so , K=8
Ans is option 8.

Like? Yes (1) | No (1)  

Anshul Ahuja   11 years AGO

because vol= side*side*sideand sideis doudleb then it become 8 times

Like? Yes (1) | No (1)  

Gayatri Lal   11 years AGO

a^3=v
8*a^3=k*v
8*a^3=a^3*k
k=8

Like? Yes (2) | No (2)  

Mukesh Kr Singh   11 years AGO

initial vol=a^3
final vol=8a^3
so 8 is ansr

Like? Yes (1) | No (1)  

N RAJU   11 years AGO

Initial Volume when side= x volume=V=x^3

later side=2x volume =(2x)^3=8(x^3)=8V

so k=8

Like? Yes (1) | No (1)  

AVINASH KUMAR   11 years AGO

let side of cube is a
volume=V=a^3
final volume=(2a)^3=8a^3
kV=8V
hence k=8

Like? Yes (2) | No (2)  

AJOY SHARMA   11 years AGO

volume = 8v^3 hence k=6

Like? Yes (2) | No (2)  

Kalpesh   11 years AGO

all sides of cubes are equal say x to the power 3 means x cube
side doubled that is 2x so the volume is 2x*2x*2x = 8x
x cube is V
8v = kv hence k = 8

Like? Yes (1) | No (1)  

Martin Raj Kumar   11 years AGO

V=a^3
kV=2a)^3
=8a^3
therefore,k=8

Like? Yes (1) | No (1)  

Devendra Marghade   11 years AGO

If each side of cube=x, then volume=V=x^3
If each side is doubled then Volume=kV=(2x)^3=8x^3
Therefore k=8

Like? Yes (1) | No (1)  

SELVI R   11 years AGO

let a be the side of a cube.
hence the volume v=a^3
if the side doubled the the new volume will be 8a^3 i.e 8v
therefore kv=8v
k=8

Like? Yes (2) | No (2)  

Kartik Nadiger   11 years AGO

New volume = kV, Old volume = V,
Volume in a cube = length * breadth * height

New Volume / Old Volume = 2l*2b*2h/ l*b*h
kV/V= 8
k=8

Like? Yes (1) | No (1)  

Ankit   11 years AGO

let side of cube = a
volume of cube = V = a^3
new volume = KV = 2a^3
=> k ( a^3 ) = 8(a^3 ) = 8V
=> k = 8

Like? Yes (2) | No (2)  

MALLIKHARJUN   11 years AGO

V= A^3
V2=(2A)^3=8A=KV=>K=8

Like? Yes (1) | No (1)  

Rats   11 years AGO

Let the side of the cube be x.
V=x^3
After doubling the side
V'=(2x)^3=8x^3=8V

Like? Yes (1) | No (2)  

Shiv Narayan Singh   11 years AGO

Let side=a
then volume(v)=a*a*a;
now side =2a;
new volume kv =2a*2a*2a;
from above it is clear that k=8

Like? Yes (1) | No (2)  

Mahendra Singh   11 years AGO

bcoz a^3=v
then (2*a)^3=8v

Like? Yes (2) | No (4)