I don\'t understand how to compare two directional systems to see if the momentu
ID: 1649844 • Letter: I
Question
I don't understand how to compare two directional systems to see if the momentum is conserved both for the individual balls and the system itself.
Ball
Mass (kg)
Initial Velocity, X Component (m/s)
Initial Velocity, Y Component (m/s)
Initial Momentum, X Component (kg*m/s)
Initial Momentum, Y Component (kg*m/s)
Final Velocity, X Component (m/s)
Final Velocity, Y Component (m/s)
Final Momentum, X Component (kg*m/s)
Final Momentum, Y Component (kg*m/s)
1
0.500
1.000
0.300
0.500
0.150
-1.348
-0.661
-0.674
-0.331
2
1.500
-0.500
-0.500
-0.750
-0.750
0.283
-0.180
0.424
-0.269
1. Compare the initial and final x momentum for ball #1. Compare the initial and final y momentum for ball #1. Is momentum conserved for the individual ball?
2. Explain your previous result based on the existence of a significant net external force (or lack thereof).
3. Compare the initial and final x momentum for ball #2. Compare the initial and final y momentum for ball #2. Is momentum conserved for the individual ball?
4. Explain your previous result based on the existence of a significant net external force (or lack thereof).
5. Calculate the total initial momentum, x component. Calculate the total final momentum, x component. Compare the two.
6. Calculate the total initial momentum, y component. Calculate the total final momentum, y component. Compare the two.
7. Is momentum conserved for the system?
8. Explain your previous result based on the existence of a significant net external force (or lack thereof).
Ball
Mass (kg)
Initial Velocity, X Component (m/s)
Initial Velocity, Y Component (m/s)
Initial Momentum, X Component (kg*m/s)
Initial Momentum, Y Component (kg*m/s)
Final Velocity, X Component (m/s)
Final Velocity, Y Component (m/s)
Final Momentum, X Component (kg*m/s)
Final Momentum, Y Component (kg*m/s)
1
0.500
1.000
0.300
0.500
0.150
-1.348
-0.661
-0.674
-0.331
2
1.500
-0.500
-0.500
-0.750
-0.750
0.283
-0.180
0.424
-0.269
Explanation / Answer
Here comparision means the difference in magnitude. As momentum is a vector quantity, any chnage in maagnitude in X and Y direction means that momemtum is not conserved.
(1) Initial and final X momentum for ball 1 are: 0.5 & -0.674 in SI units.
Initial and final Y momentum for ball 1 are: 0.150 & -0.331.Momentum is hence not conserved for individual balls.
(2) As there is a change in momentum and hence there must be an external force on the ball 1. This force may however be due to the collision with ball 2. And there may not be a net external force on the system of two balls, just interaction between these two balls.
(3) Next steps are as it is for ball 2. So (3) and (4) i suppose are understood.
(5) Total initial X momentum is sum of X momentum of both balls, i.e. 0.500 - 0.750 = -0.250 SI units.
Final X momentum is sum of both final X momentums: -0.674 + 0.424 = -0.250 SI units. Hence these are same, no net external force in X direction.
(6) total initial Y momentum : 0.150-0.750 = -0.600 SI units
Total final Y momentum : -0.331 -0.269 = -0.600 SI units.
(7) the total momentum of the system is conserved as there in no change in momemtum in any direction.
(8) As total momentum of the system is conserved, there in mo external force on the system.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.