Momentum In Space Simulation
Name ___________________________________________________ Pd___
AstroPitch
Simulation Assumptions:
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The mass of the astronaut is 120 kilograms (including his/her life support
equipment).
The mass of all the thrown objects (baseballs) is 0.5 kilograms.
The loss of baseballs by the astronaut does not change his/her net
mass.
There are no net initial forces acting on the astronaut (
Motion to the right is positive and motion to the left is a negative velocity.
The astronaut and the baseballs are an isolated system in deep space.
Momentum Facts
o
Momentum = mass times velocity or P = mV = m(Vf - Vo)
Initial Momentum = Final Momentum
(Pi = Po)
(mV)1 + (mV)2 = (mV)1' + (mV)2'
Activity:
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Press the AstroPitch Tab at the top of the screen.
Observe the astronaut is at rest in space.
What is the initial momentum of the astronaut? _________________
Why is the initial momentum of the astronaut this value?
With the astronaut facing to the right of the monitor screen, select a ball speed of 10 m/s
and press the "pitch" button one time.
What is the velocity of the thrown ball? _________________________
Using the momentum equation above calculate the momentum of the baseball.
_______________ kg.m/s
What is the moving direction of the astronaut after the ball is thrown (positive or negative)?
_____________________
What is the momentum of the astronaut after throwing one pitch? _________ kg.m/s.
What is the velocity of the astronaut after throwing one pitch at +10 m/s? _________
Does the observed velocity of the astronaut change after throwing the +10 m/s pitch?
_______
Why does the astronaut keep moving in a straight line at constant speed?
i. ___________________________________________________________
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What is the total final momentum of the astronaut-baseball system? _____________
How does this compare to the total initial momentum of the astronaut-baseball system?
_____________________________________________________
When will the astronaut come to rest? ______________________________________
How could the astronaut stop his/her motion?
_______________________________________________________
Press the reset button.
Again throw one baseball at +10 m/s. Turn the astronaut to face in the other direction.
Again throw a baseball, but this time its velocity will be -10 m/s.
Why is the astronaut observed to stop his motion? __________________
20. This time, have the astronaut throw a baseball with a velocity of +50 m/s. How does the
speed of the astronaut's motion compare to when he/she threw a baseball at +10 m/s?
_____________________________
21. How many baseballs with a velocity of -10 m/s must be thrown to stop his motion after
throwing only one baseball at +50 m/s? _____________
22. Test your answer to Question #21. Turn the astronaut to face in the negative direction and
throw baseballs at -10 m/s to stop his motion produced when one baseball was thrown at
+50 m/s. How many where thrown at -10 m/s to stop his motion? ______________
23. When the velocity of an object of constant mass is increased by a factor of five, its
momentum is increased by a factor of ____________.
24. Does the conservation law of momentum apply to weightless objects? ________
25. Do objects in space have mass? _____________
26. Do objects in space accelerate according to the laws of physics: F = ma or F.
V?
________________
27. When a baseball is thrown, compare the velocities of the baseball and astronaut.
28. When a baseball is thrown, compare the momentum of the baseball and astronaut.
29. Press the reset button.
30. Throw a baseball at +25 m/s. Turn the astronaut around. Throw two baseballs at -10 m/s.
What is the sum of these three baseball velocities? __________ The observed motion of
the astronaut could have been produced by throwing one baseball at a speed of
___________ in the positive direction.
Complete the Chart below, use the program if necessary to determine the
answers and use the assumption data provided at the beginning of this
program.
Data Table #1
Initial total
Momentum
Baseball
Mass
Baseball
Velocity
(m/s)
Baseball
Momentum
(kg.m/s)
Astronaut
Mass
(kg.m/s)
(kg)
0
0.5
+60
120 kg
0
0.5
-15
120 kg
0
0.5
+55
120 kg
0
0.5
+105
120 kg
0
0.5
-75
120 kg
0
0.5
+90
120 kg
0
0.5
+35
120 kg
0
0.5
+145
120 kg
(kg)
Conclusion: Summarize how a stationary astronaut in space is able to move
when there is nothing to touch but the objects in his/her hands or pockets.
Astronaut
Velocity
(m/s)
Astronaut
Momentum
(kg.m/s)