Your 'cq_1_24.2' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** **
A steel ball of mass 60 grams, moving at 80 cm / sec, collides with a stationary marble of mass 20 grams. As a result of the collision the steel ball slows to 50 cm / sec and the marble speeds up to 70 cm / sec.
• Is the total momentum of the system after collision the same as the total momentum before?
answer/question/discussion: Yes. Conservation of momentum says that the momentum before must equal the momentum after the collision. Thus, we know m1v1 + m2v1 = m1v2 + m2v2.
Conservation of momentum applies to isolated systems. If you calculate the total momentum before and after collision you will find that it is not conserved.
• What would the marble velocity have to be in order to exactly conserve momentum?
answer/question/discussion: To use m1v1 + m2v1 = m1v2 + m2v2 we get (60 g) * 80 cm/s = 60 g * 50 cm/s + 20 g * v2 so that 4800 gcm/s = 3000gcm/s + 20v2. Therefore, v2 = 90 cm/s.
&#Good work. See my notes and let me know if you have questions. &#
Your 'cq_1_24.2' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** **
A steel ball of mass 60 grams, moving at 80 cm / sec, collides with a stationary marble of mass 20 grams. As a result of the collision the steel ball slows to 50 cm / sec and the marble speeds up to 70 cm / sec.
• Is the total momentum of the system after collision the same as the total momentum before?
answer/question/discussion: Yes. Conservation of momentum says that the momentum before must equal the momentum after the collision. Thus, we know m1v1 + m2v1 = m1v2 + m2v2.
Conservation of momentum applies to isolated systems. If you calculate the total momentum before and after collision you will find that it is not conserved.
• What would the marble velocity have to be in order to exactly conserve momentum?
answer/question/discussion: To use m1v1 + m2v1 = m1v2 + m2v2 we get (60 g) * 80 cm/s = 60 g * 50 cm/s + 20 g * v2 so that 4800 gcm/s = 3000gcm/s + 20v2. Therefore, v2 = 90 cm/s.
&#Good work. See my notes and let me know if you have questions. &#