physics

posted by .

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

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics-collisions

    An internal explosion breaks an object, initially at rest, into two pieces, one of which has 2 times the mass of the other. If 22500 J is released in the explosion, how much kinetic energy does each piece acquire?
  2. college physics

    A 915 kg two-stage rocket is traveling at a speed of 5.50×10^3 m/s with respect to Earth when a pre-designed explosion separates the rocket into two sections of equal mass that then move at a speed of 4.00×10^3 m/s relative to each …
  3. physics

    A 8.00 kg shell at rest explodes into two fragments, one with a mass of 2.00 kg and the other with a mass of 6.00 kg. If the heavier fragment gains 130 J of kinetic energy from the explosion, how much kinetic energy does the lighter …
  4. p

    An explosion breaks a 10 kg object (originally at rest) into two pieces, one of which is two times the mass of the other. If 8000 J is released in the explosion, a) how fast are the pieces moving away from their original location?
  5. Physics

    A 6.2 kg model rocket is traveling horizontally and due south with a speed of 20.3 m/s when it explodes into two pieces. The velocity of one piece, with a mass of 1.6 kg, is v1 = (-12 m/s)i + (30 m/s)j + (15 m/s)k, with i pointing …
  6. Physics

    An explosion breaks an object into two pieces, one of which has 2 times the mass of the other. If 22500 J were released in the explosion, of which 21% is heat, how much kinetic energy did each piece acquire?
  7. physics

    A 41.0-kg body is moving in the direction of the positive x axis with a speed of 306 m/s when, owing to an internal explosion, it breaks into three pieces. One part, whose mass is 8.0 kg, moves away from the point of explosion with …
  8. physics

    A 2.40 kg firecracker explodes into two pieces and produces 170 J of heat, light, and sound energy. One of the pieces has a mass of 0.800 kg and a speed of 4.50 m/s after the explosion. If the mass of the other piece is 1.20 kg, what …
  9. COLLEGE PHYSICS

    An internal explosion breaks an object, initially at rest, into two pieces. One piece (m1) is 1.5 times more massive than the other (m2). If 7500 J were released by the explosion, how much KE did each piece acquire?
  10. Physics

    An explosion breaks an object initially at rest into two pieces, one of which has 2.0 times the mass of the other. If 7300 J of kinetic energy were released in the explosion, how much kinetic energy did the lighter piece acquire?

More Similar Questions