Phet_momentum_lab- Khalid 18291b

Name: Khaled Al Qabqab Momentum Lab Directions: Go to http://phet.colorado.edu/en/simulation/collision-lab and click Run Now.

Comment [E1]: 68/100

Make sure the 1-d box is checked. Part 1 Scenario #1: Elastic collision between balls of equal mass Make a hypothesis about initial and final momentums before playing with the sim. According to me, the initial and final momentums of the summation of both the balls will remain same. Or in other words, the total initial and the total final momentum will remain same.

Comment [E2]: 3/3

Make a data table for the following: mass, velocity and momentum of each ball before and after. Before Collision Ball 1 2

Mass (kg) 1.5 1.5

Velocity (m/s) 0.5 -1

Momentum (Ns) 0.75 -1.5 Total: -0.75

After Collision 1 2

1.5 1.5

-1 0.5

1.5 -0.75 Total: -0.75

What is the relationship between the initial and final total momentums? Initial and final momentums of both balls are related as per the conservation of momentum phenomena. The law of conservation states that in an elastic collision, both the momentum and K.E remains same. Hence the initial and final momentum are related as:

Comment [E3]: 5/6

Comment [E4]: 4/4

Total initial momentum = Total final momentum m1u1+m2u2 = m1v1+m2v2 where u1 and u2 are the initial velocities of mass m1 and m2 whereas the v1 and v2 are the final velocities of the mass m1 and m2 respectively. Describe the motion of the balls before and after the collision? As per the law, the balls exchange their kinetic energy and momentum equally with one another hence keeping the overall momentum conserved. This is why the velocity of ball 1 is attained by the ball 2 as well as its direction after the collision and exactly the opposite is done by the ball 1 and both of the balls exchange their directions hence presenting a perfect inelastic collision case.

Comment [E5]: 6/7

Scenario #2: Elastic collision between balls of unequal mass. Make a hypothesis about initial and final momentums before playing with the sim. According to me, the initial and final momentums of the summation of both the balls will remain same. Or in other words, the total initial and the total final momentum will remain same. Make a data table for the following: mass, velocity and momentum of each ball before and after. Before Collision Ball 1 2

Mass (kg) 1 1.5

Velocity (m/s) 0.5 -1

Momentum (Ns) 0.5 -1.5 Total: -1

After Collision 1 2

1 1.5

-1.3 0.2

-1.3 0.3 Total: -1

What is the relationship between the initial and final total momentums? Initial and final momentums of both balls are related as per the conservation of momentum phenomena. The law of conservation states that in an elastic collision, both the momentum and K.E remains same. Hence the initial and final momentum are related as:

Comment [E6]: 5/6

Comment [E7]: 2/4

Total initial momentum = Total final momentum m1u1+m2u2 = m1v1+m2v2 where u1 and u2 are the initial velocities of mass m1 and m2 whereas the v1 and v2 are the final velocities of the mass m1 and m2 respectively. Your answer here is too generalized. You should have directed it to the question at hand Describe the motion of the balls before and after the collision? As per the law, the balls exchange their kinetic energy and momentum equally with one another hence keeping the overall momentum conserved. The direction of both balls change i.e. it gets opposite to what it was before collision. The magnitude of their velocities change as per the law of conservation to keep momentum same. Thus the heavier mass becomes slower (gives all of its momentum and K.E to another ball) and the lighter mass attains higher velocity. Part 2 Create 3 more distinct scenarios in 1-d including one totally inelastic collision. Make a hypothesis whether or not each will follow conservation of momentum. Collect some data and prove or disprove your hypothesis.

Comment [E8]: 5/7

Summary: Describe the main ideas learned in this activity regarding initial and final total momentum in 1-d collisions. Scenario #1: InElastic collision between balls of unequal mass. Hypothesis: According to me, the initial and final momentums of the summation of both the balls will remain same. Or in other words, the total initial and the total final momentum will remain same. But the K.E will not be conserved. So both balls will have same velocity after collision given by the formula:

Comment [E9]: 5/5

Results from Sim: Before Collision Ball 1 2

Mass (kg) 1 1.5

Velocity (m/s) 0.5 -1

Momentum (Ns) 0.5 -1.5 Total: -1

After Collision 1 2

1 1.5

-0.4 -0.4

-0.4 -0.6 Total: -1

Conclusion: Hence the results are in conjunction with the hypothesis and are a proof of the analogy that momentum always remain same whether it is the elastic collision or an inelastic collision. The only thing which varies is the energy (K.E) in this case which gets transfers to other forms in of restitution.

Comment [E10]: 4/5

Comment [E11]: 4/5

Scenario #2: InElastic collision between balls of equal mass. Hypothesis: According to me, the initial and final momentums of the summation of both the balls will remain same. Or in other words, the total initial and the total final momentum will remain same. But the K.E will not be conserved. So both balls will have same velocity after collision given by the formula:

Comment [E12]: 3/5

What is the difference between this hypothesis and the one for scenario #1? Results from Sim: Before Collision Ball 1 2

Mass (kg) 1.5 1.5

Velocity (m/s) 0.5 -1

Momentum (Ns) 0.75 -1.5 Total: -0.75

After Collision 1 2

1.5 1.5

-0.25 -0.25

-0.375 -0.375 Total: -0.75

Conclusion: Hence the results are in conjunction with the hypothesis and are a proof of the analogy that momentum always remain same whether it is the elastic collision or an inelastic collision. The only thing which varies is the energy (K.E) in this case which gets transfers to other forms in of restitution.

Comment [E13]: 4/5

Comment [E14]: 4/5

Scenario #3: InElastic collision between balls of equal mass with equal speed. Hypothesis: According to me, the initial and final momentums of the summation of both the balls will remain same. Or in other words, the total initial and the total final momentum will remain same. But the K.E will not be conserved. So both balls will have same velocity after collision given by the formula:

Comment [E15]: 3/5

Results from Sim: Before Collision Ball 1 2

Mass (kg) 1.5 1.5

Velocity (m/s) 1 -1

Momentum (Ns) 1.5 -1.5 Total: 0.00

After Collision 1 2

1.5 1.5

0 0

0.00 0.00 Total: 0.00

Comment [E16]: 5/5

Conclusion: Hence the results are in conjunction with the hypothesis and are a proof of the analogy that momentum always remain same whether it is the elastic collision or an inelastic collision. The only thing which varies is the energy (K.E) in this case which gets transfers to other forms in of restitution. Where is your summary?

Comment [E17]: 4/5