Calculating Kinetic Energy of Meteor

[vandorin]

Homework Statement

What is the Kineti energy of a 1g (0.001kg) meteor traveling at 30,000m/s? Express your answer in Joules.

Homework Equations

KE=1/2MV^2

The Attempt at a Solution

1/2(.001kg)(30,000)^2 = 450000J


Now since 30,000 is squared, would i have to multiply .001kg by 4, before i did all of this math?

 

[foxjwill]

Nope. You just plug .001kg in for M. Out of curiosity, why would you multiply by 4?

 

[vandorin]

I thought that since v is squared, you had to multiply the mass by 4...or is that only if its 2v^2?

 

[gendou2]

I thought that since v is squared, you had to multiply the mass by 4...or is that only if its 2v^2?

Nope, the one half is a separate term from the squared term:

KE = (1/2) * (m) * (v²)