Solving Kinetic Energy: How Do I Rearrange the Equation for Mass?

[thomas49th]

Hi, I know the kinetic energy equation is

Kinetic Energy(J) = 0.5 x Mass (Kg) x velocity² (m/s)

So how do I rearrange it. I've been having problems with it

I have a question here

What is the weight of an object traveling at 2m/s with 2J of kinetic energy?


the answer is 10N, but how?

Thanks

 

[radou]

What is the weight of an object traveling at 2m/s with 2J of kinetic energy?

If you know the velocity and the kinetic energy of the object, what can you calculate from the definition of kinetic energy? You wrote it down already.

 

[Ja4Coltrane]

write it like this
2J=(1/2)m(2m/s)^2
algebra.
then you need to get weight from mass.

 

[thomas49th]

1N so weight is

1 x 10 = 10N/Kg?

 

[radou]

1N so weight is

1 x 10 = 10N/Kg?

If you round up g to equal 10, then you have W = mg = 1 [kg] * 10 [m/s^2] = 10 [kg m /s^2] = 10 [N] ! Watch out for units!