8TH GRADE UNIT ON ACCELERATION, MOMENTUM AND COLLISIONS Name _________________
PART 1 OF 2
DUE DATE: WEDNESDAY MAY 11
Chapter 18, Section 1
1. Define “MOTION”: __________________________________________________________________
______________________________________________________________________________________
2. Complete both Motion Lab 1 AND Motion Lab 2.
3. If you travel through a city for a TOTAL of 6 km in 30 minutes, what is your AVERAGE speed?
4. Given the data in question 3, is it possible to calculate/know if your speed was CONSTANT?
Explain your answer
______________________________________________________________________________________
______________________________________________________________________________________
5. Define “VELOCITY” : ________________________________________________________________
______________________________________________________________________________________
6. You run “around” a circular track with a constant speed of 6 km/hr. Explain in the space below why your
VELOCITY is NOT constant even though your speed is constant.
Explain: ______________________________________________________________________________
______________________________________________________________________________________
Chapter 18, Section 2
7. Define “ACCELERATION”: ___________________________________________________________
______________________________________________________________________________________
8. Understanding acceleration means knowing that acceleration involves a change in an objects ___________
OR a change in it’s __________________ of motion OR changes in _____________ of these.
Chapter 18, Section 3
9. Define “INERTIA”: _________________________________________________________________
______________________________________________________________________________________
10. Define “MOMENTUM”: ______________________________________________________________
______________________________________________________________________________________
11. What is the EQUATION FOR MOMENTUM? ____________________________________________
12. Solve the “Practice Problems” at the bottom of page 534 including the correct unit of measure with your
answer and show your math below.
1.
2.
13. Define: “LAW OF CONSERVATION OF MOMENTUM”: ___________________________________
________________________________________________________________________________________
8TH GRADE UNIT ON ACCELERATION, MOMENTUM AND COLLISIONS Name _________________
PART 2 OF 2
DUE DATE: FRIDAY MAY 13
14. Complete the “Elastic Collisions and Momentum Activity page”
15. Complete the “Inelastic Collisions and Momentum Activity page”
16. Which has more momentum? A grain of sand falling to the ground or a brick resting on the ground?
Explain: ________________________________________________________________________________
________________________________________________________________________________________
17. If two objects collide, their INDIVIDUAL __________________ can be different BEFORE and AFTER
the collision, but the TOTAL ____________________ of the system (all objects involved in the collision) must
be the same BEFORE and AFTER the collision. This follows the Law of __________________________
________ _______________________.
Chapter 19, Section 1
18. Define “NET FORCE”: ________________________________________________________________
______________________________________________________________________________________
19. When the NET FORCE applied to an object is NOT ______________, it’s motion will change. If the
motion of an object changes, its ___________________ changes. A change in velocity means the object is
________________________.
18. Define “BALANCED FORCES”: _______________________________________________________
_______________________________________________________________________________________
19. Define “UNBALANCED FORCES”: ____________________________________________________
_______________________________________________________________________________________
20. Forces never act alone, but occur in _______________ as described in Newtons 3rd Law.
21. Friction comes in several forms, but always resists the motion of an object causing them to
______________ ______________.
22. Equal forces acting in opposite directions will always produce a NET FORCE of ______________
therefore those forces must be ______________________ forces.
23. Air resistance is a form of _____________________. ANY object falling downward through the air is
affected by this force which has an _____________________ direction since falling objects move
____________________ through the air toward the ground.
24. How does air resistance change when an object travels faster? ________________________________
_______________________________________________________________________________________
Motion Lab 1: Distance vs. Displacement
Procedure:
1. Measure the distance between each stop centimeters on the route ACCURATE TO ONE DECIMAL
PLACE (eg; 3.3 cm) and record in a data table (make one in the space below where you will record the distance
between each stop. Include the total distance traveled.
2. This map has a scale of
1cm = 1km so the REAL distance traveled can be determined easily.
3. Answer the following questions.
What is the total distance traveled in kilometers?
What is the DISPLACEMENT of the traveler at the last stop in kilometers?
Motion Lab 2: Calculating and Graphing SPEED
Procedure:
What is SPEED: _____________________________________________________________________
What is the EQUATION for SPEED: _____________________
What is AVERAGE SPEED: ___________________________________________________________
What is INSTANTANEOUS SPEED: ____________________________________________________
1. Make another data table in the space according to and IN ORDER of the bullet points as shown below.
■ distance between each stop in km (take from Motion Lab 1 data table)
■ time it takes to go between each stop in hours (see below)
■ average speed between each stop in km/hr (calculate using speed equation)
■ distance traveled from the start along the route to each stop (calculate)
■ time the driver stays at each stop unloading cases of Red Bull
The following times taken were noted as the driver went between each stop:
(put these into your data table)
From Start to Stop 1: 0.5 hours; Stays at Stop 1: 0.25 hours (not moving)
From Stop 1 to Stop 2: 0.25 hours; Stays at Stop 2: 0.25 hours (not moving)
From Stop 2 to Stop 3: 0.20 hours; Stays at Stop 3: 0.25 hours (not moving)
From Stop 3 to Stop 4: 1.0 hours; Stays at Stop 4: 0.25 hours (not moving)
From Stop 4 to Last Stop: 0.75 hours; Driver stays at the last stop indefinitely
2. Using the information from your data table, create a SPEED graph on the back of this page that shows
Distance versus Time of the delivery man’s travels for the day. (Read page 526 and then see the example in
figure 5 page on the same page – YOUR GRAPH WILL LOOK DIFFERENT!)
Lab Questions
Procedure:
Answer the questions below in COMPLETE SENTENCES.
1. What was the AVERAGE SPEED of the driver from the START of the route to the LAST STOP?
2. Is your answer in question 1 different than the speeds you calculated between each stop?
Explain your answer in complete sentences.
___________________________________________________________________________________
___________________________________________________________________________________
___________________________________________________________________________________
4. Between which stops did the driver have the FASTEST speed? _____________________________
5. Between which stops did the driver have the SLOWEST speed? _____________________________
6. How does the line on the graph where he was traveling at the highest speed compare to where he was
traveling at the slowest speed?
Explain:____________________________________________________________________________
___________________________________________________________________________________
___________________________________________________________________________________
7. If only looking at the graph, how would a person know the drivers speed is zero in some places?
___________________________________________________________________________________
Elastic Collisions and Momentum Activity
Name ___________
This activity requires the use of the internet. Use the link on Mr. Polidoro’s home page marked
Collisions and Momentum or use the following URL: http://mrphome.net/physics/ph14e/collision.htm
This simulation allows you to collide vehicles with different masses and with different velocities. When you arrive to the
simulation set it up as follows:
POSITIVE 0.5 m/s (makes wagon go to right)
Set the velocity of the BLUE wagon to NEGATIVE 0.5 m/s (makes wagon go to left)
Set or make sure masses for BOTH wagons are set to 0.5 kg
1. Set the velocity of the RED wagon to
2. Make sure the following buttons are selected for an “Elastic Collision” and to observe “Velocity”.
3. Write the formula for MOMENTUM here
4. Click the yellow “Start” button to watch the collision. Reset then start again to repeat.
EXPERIMENT
ELASTIC COLLISIONS WITH VEHICLES HAVING THE SAME MASS.
In the space below find a table where you will record data about the RED and BLUE wagons. For each wagon you need
to record the data for this experiment.
VELOCITY
MOMENTUM
VELOCITY
MOMENTUM
WAGON
MASS
BEFORE
BEFORE
AFTER
AFTER
COLLISION
COLLISION
COLLISION
COLLISION
RED
BLUE
1. Enter the mass, initial and final velocities for BOTH wagons from the simulation screen into your data table MAKING
SURE YOU SHOW IF IT’S NEGATIVE OR NOT AND INCLUDE THE UNITS OF MEASURE.
2. Calculate the BEFOR MOMENTUM and AFTER MOMENTUM for each wagon and enter into data table MAKING
SURE YOU SHOW IF IT’S NEGATIVE OR NOT AND INCLUDE THE UNITS OF MEASURE.
Questions:
1. What was the total combined initial momentum of both wagons BEFORE the collision? (include units) ___________
2. What was the total combined final momentum of both wagons AFTER the collision? (include units) _____________
3. Was momentum CONSERVED from before to after the collision? ___________
Explain your answer from question 3. _______________________________________________________________
_____________________________________________________________________________________________
SET UP FOR NEXT EXPERIMENT:
POSITIVE 0.5 m/s (makes wagon go to right)
Keep the VELOCITY of the BLUE wagon set to NEGATIVE 0.5 m/s (makes wagon go to left)
Set the MASS for the RED wagon to 1 kg and make the BLUE one 0.2 kg
1. Now, keep the VELOCITY of the RED wagon set to
2. Make sure the following buttons are selected for an “Elastic Collision” and to observe “Velocity”.
3. Click the yellow “Start” button to watch the collision. Reset then start again to repeat.
EXPERIMENT
ELASTIC COLLISIONS WITH VEHICLES HAVING DIFFERENT MASSES.
In the space below find a table where you will record data about the RED and BLUE wagons. For each wagon you need
to record the data for this experiment.
VELOCITY
MOMENTUM
VELOCITY
MOMENTUM
WAGON
MASS
BEFORE
BEFORE
AFTER
AFTER
COLLISION
COLLISION
COLLISION
COLLISION
RED
BLUE
1. Enter the mass, initial and final velocities for BOTH wagons from the simulation screen into your data table MAKING
SURE YOU SHOW IF IT’S NEGATIVE OR NOT AND INCLUDE THE UNITS OF MEASURE.
2. Calculate the BEFOR MOMENTUM and AFTER MOMENTUM for each wagon and enter into data table MAKING
SURE YOU SHOW IF IT’S NEGATIVE OR NOT AND INCLUDE THE UNITS OF MEASURE.
Questions:
ROUND TO ONE DECIMAL
1. What was the total combined initial momentum of both wagons BEFORE the collision? (include units) ___________
2. What was the total combined final momentum of both wagons AFTER the collision? (include units) _____________
3. Was momentum CONSERVED from before to after the collision? ___________
Explain your answer from question 3. _______________________________________________________________
_____________________________________________________________________________________________
Inelastic Collisions and Momentum Activity
Name ___________
This activity requires the use of the internet. Use the link on Mr. Polidoro’s home page marked
Collisions and Momentum or use the following URL: http://mrphome.net/physics/ph14e/collision.htm
This simulation allows you to collide vehicles with different masses and with different velocities. When you arrive to the
simulation set it up as follows:
POSITIVE 0.5 m/s (makes wagon go to right)
Set the velocity of the BLUE wagon to NEGATIVE 0.5 m/s (makes wagon go to left)
Set or make sure masses are set for BOTH wagons to 0.5 kg
1. Set the velocity of the RED wagon to
2. Make sure the following buttons are selected for an “Inelastic
Collision” and to observe “Velocity”.
3. Write the formula for MOMENTUM here
4. Click the yellow “Start” button to watch the collision. Reset then start again to repeat.
EXPERIMENT
INELASTIC COLLISIONS WITH VEHICLES HAVING THE SAME MASS.
In the space below find a table where you will record data about the RED and BLUE wagons. For each wagon you need
to record the data for this experiment.
VELOCITY
MOMENTUM
VELOCITY
MOMENTUM
WAGON
MASS
BEFORE
BEFORE
AFTER
AFTER
COLLISION
COLLISION
COLLISION
COLLISION
RED
BLUE
1. Enter the mass, initial and final velocities for BOTH wagons from the simulation screen into your data table MAKING
SURE YOU SHOW IF IT’S NEGATIVE OR NOT AND INCLUDE THE UNITS OF MEASURE.
2. Calculate the BEFOR MOMENTUM and AFTER MOMENTUM for each wagon and enter into data table MAKING
SURE YOU SHOW IF IT’S NEGATIVE OR NOT AND INCLUDE THE UNITS OF MEASURE.
Questions:
1. What was the total combined initial momentum of both wagons BEFORE the collision? (include units) ___________
2. What was the total combined final momentum of both wagons AFTER the collision? (include units) _____________
3. Was momentum CONSERVED from before to after the collision? ___________
Explain your answer from question 3. _______________________________________________________________
_____________________________________________________________________________________________
SET UP FOR NEXT EXPERIMENT:
POSITIVE 0.5 m/s (makes wagon go to right)
Keep the VELOCITY of the BLUE wagon set to NEGATIVE 0.5 m/s (makes wagon go to left)
Set the MASS for the RED wagon to 1 kg and make the BLUE one 0.2 kg
1. Now, keep the VELOCITY of the RED wagon set to
2. Make sure the following buttons are selected for an “Inelastic
Collision” and to observe “Velocity”.
4. Click the yellow “Start” button to watch the collision. Reset then start again to repeat.
EXPERIMENT
INELASTIC COLLISIONS WITH VEHICLES HAVING THE SAME MASS.
In the space below find a table where you will record data about the RED and BLUE wagons. For each wagon you need
to record the data for this experiment.
VELOCITY
MOMENTUM
VELOCITY
MOMENTUM
BEFORE
BEFORE
AFTER
AFTER
WAGON
MASS
COLLISION
COLLISION
COLLISION
COLLISION
RED
BLUE
1. Enter the mass, initial and final velocities for BOTH wagons from the simulation screen into your data table MAKING
SURE YOU SHOW IF IT’S NEGATIVE OR NOT AND INCLUDE THE UNITS OF MEASURE.
2. Calculate the BEFOR MOMENTUM and AFTER MOMENTUM for each wagon and enter into data table MAKING
SURE YOU SHOW IF IT’S NEGATIVE OR NOT AND INCLUDE THE UNITS OF MEASURE.
Questions:
ROUND TO ONE DECIMAL
1. What was the total combined initial momentum of both wagons BEFORE the collision? (include units) ___________
2. What was the total combined final momentum of both wagons AFTER the collision? (include units) _____________
3. Was momentum CONSERVED from before to after the collision? ___________
Explain your answer from question 3. _______________________________________________________________
_____________________________________________________________________________________________
4. What is the difference between an ELASTIC vs INELASTIC collision? ___________________________________
_____________________________________________________________________________________________