hello i need help in solving this
Q)If the speed of a vehicle increases by 2 m/s,its kinetic energy is doubled,then original speed of the vehicle is
a)(sqrt of 2 )+1 m/s

b)2(sqrt of 2 -1)m/s

c)2(sqrt of 2 + 1 )m/s

d)sqrt of 2 (sqrt of 2 + 1)m/s

sqrt is square root of

please help me out

Thnx in advance

Edited February 7, 201411 yr by Jay Sharma

What's the equation for KE?

there is no equation given for K.E

there is no equation given for K.E

 

What is classical Kinetic Energy equation that you learn in the first class of physics?

ok that is K.E=1/2 m*v²

So equation to solve will be:

 

1/2*m*(v+2)^2 = 1/2*m*v^2 * 2

m is common, solve v.

so i got v=2 so how do i find the correct option

that isnt an option in question

so i got v=2 so how do i find the correct option

 

 

It's not the right answer.

 

I entered it to OpenOffice

A column is velocity

B column is K.E. with v

C column is. K.E. with v+2

D column is C/2

 

 

See where they're crossing..

 

 

You should not guess, but calculate..

 

v^2-4*v-4=0

 

Edited February 7, 201411 yr by Sensei

 

It's not the right answer.

 

I entered it to OpenOffice

A column is velocity

B column is K.E. with v

C column is. K.E. with v+2

D column is C/2

Kinetic Energy table.png

 

See where they're crossing..

 

You should not guess, but calculate..

 

v^2-4*v-4=0

 

oh sorry i had taven -4 as +4 sorry for that

thank you sensai for your help

i found that the option c (c)2(sqrt of 2 + 1 )m/s)is correct please just crosscheck it once please

thank you please help me in my others questions in my other posts please

please cross check it

and help me in other questions please

V equal approximately 4.828 is the answer.

 

2* (sqrt(2)+1) = ~4.828

V equal approximately 4.828 is the answer.

 

2* (sqrt(2)+1) = ~4.828

is that means i m right

if yes then please help me in my other posts too

if no then also help me

!

Moderator Note

Members should be aware that the OP Jay Sharma has been banned as a sockpuppet of Rajnish Kaushik.