PDA

View Full Version : Kinetic Energy


vandorin
May27-08, 02:26 PM
1. The problem statement, all variables and given/known data

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

2. Relevant equations
KE=1/2MV^2


3. 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
May27-08, 03:25 PM
Nope. You just plug .001kg in for M. Out of curiosity, why would you multiply by 4?

vandorin
May27-08, 04:48 PM
I thought that since v is squared, you had to multiply the mass by 4.......or is that only if its 2v^2?

gendou2
May27-08, 04:54 PM
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)