# A mass of 1x10^-16 kg is traveling, what is its kinetic energy ?

xterminal01

## Homework Statement

A mass of 1x10^-16 kg is traveling at 0.5 c to the nearest hundredth joule what is its kinetic energy?

## Homework Equations

Et=KE + mc^2=Jmc^2
KE=mc^2(J-1)
KE=mc^2(1/sqrt(1-v^2/c^2)-1)=

## The Attempt at a Solution

This is where i am stuck putting the whole thing in the calculator i guess...
(1X10^-16)(.5)^2(1x10^-16)(3x10^8)^2(1/sqrt(1-0.5^2)^2-1)
answer is 1.39, i keep getting something else?

## Homework Statement

A mass of 1x10^-16 kg is traveling at 0.5 c to the nearest hundredth joule what is its kinetic energy?

## Homework Equations

Et=KE + mc^2=Jmc^2
KE=mc^2(J-1)
KE=mc^2(1/sqrt(1-v^2/c^2)-1)=

So far so good.

## The Attempt at a Solution

This is where i am stuck putting the whole thing in the calculator i guess...
(1X10^-16)(.5)^2(1x10^-16)(3x10^8)^2(1/sqrt(1-0.5^2)^2-1)

This doesn't look much like the formula you just gave. The formula you had was mc^2(1/sqrt(1-v^2/c^2)-1)

xterminal01
How should i set the equation up ?

How should i set the equation up ?

Just use the formula you gave, with the values for all the variables. I don't know what happened for the numbers... but for example, the mass is 10-16. Mass appears just one in your formula, but twice in the list of numbers you gave for the calculator.

[highlight](1X10^-16)[/highlight](.5)^2[highlight](1x10^-16)[/highlight](3x10^8)^2(1/sqrt(1-0.5^2)^2-1)​

xterminal01
Can you show what to input into the calculator to get 1.39J, because that's actually where i am stuck. Thanks

Staff Emeritus