Sunday
March 29, 2015

Homework Help: physics

Posted by micole on Tuesday, May 29, 2007 at 11:35am.

An explosion breaks an object into two pieces, one of which has 3.20 times the mass of the other. If 8000 J were released in the explosion, how much kinetic energy did each piece acquire?
I started with using KE = (1/2)mv^2 and m1v1 = m2v2. Then (1/2)m1(v1)^2 + (1/2)m2(v2)^2 = 8000J. How do I find the velocities? I tried rearranging the equations to solve for one of the unknowns, but got stuck.

Momentum is conserved. The initial momentum is zero, therefore:

m1 v1 + m2 v2 = 0 ---->

m1 v1 = m2 v2 ----->

(m1 v1)^2 = (m2 v2)^2

1/2 m1 v1^2 = 1/2 m2 v2^2 * (m2/m1)

So, you have:

KE1 + KE2 = 8000 J

and:

KE1 = (m2/m1) KE2

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

p - An explosion breaks a 10 kg object (originally at rest) into two pieces, one...
Physics - An explosion breaks an object into two pieces, one of which has 2 ...
Physics - An explosion breaks an object initially at rest into two pieces, one ...
physics-collisions - An internal explosion breaks an object, initially at rest, ...
COLLEGE PHYSICS - An internal explosion breaks an object, initially at rest, ...
physics - A 2.40 kg firecracker explodes into two pieces and produces 170 J of ...
Physics - A 6.2 kg model rocket is traveling horizontally and due south with a ...
physics - A 41.0-kg body is moving in the direction of the positive x axis with ...
college physics - A 915 kg two-stage rocket is traveling at a speed of 5.5010^3...
physics - A 8.00 kg shell at rest explodes into two fragments, one with a mass ...

Members