CHS PHYSICS
Name: _________________ Period: ___
V IRTUAL IRTUAL COLLISIONS L AB OBJECTIVE: To experiment with and gain a better understanding of collisions and the Conservation of Momentum. EQUATIONS: Conservation of Momentum states that the total initial momentum is equal to the total nal momentum in the absence of IMPU!" #ΔP $ %Δt&. That is to sa' if there is no net force the total initial momentum equals the total nal
momentum. ΣPi $ ΣPf
Pai (Pbi $ Paf (P (Pbf ma v vai (mb v vbi $ ma v vaf (m (mb v vbf
GETTING STARTED: •
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download the program or if 'ou would li,e to run the program) select o,a') or run.
Turn on the computer and open an %irefox) or Internet "xplorer. "xplorer. In the U* address t'pe+ http://phet.colorado.ed/e!/"#$la t#o!/coll#"#o!%la& If this U* does not wor, properl' go to http+--phet.colorado.edu !elect+ Pla' with sims !elect+ Ph'sics !croll down and select+ Collisions ab
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ou ou ma' be prompted to
!elect the / dimension setting on the panel in the upper right corner of the screen. The following boxes should be chec,ed+ 0elocit' 0ectors) *e1ecting 2order) Momenta 3iagram) and !how Paths. To start set the elasticit' set at
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!elect+ R! No'( ◦
The Collisions Lab Simulator program should now be open.
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!elect the More 3ata 2utton at the bottom of the screen.
)ER*ECTL+ ELASTIC COLLISION: •
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Investigate the action of a $ore%$a""#,e attac-#! o&ect "tr#-#! a le""% $a""#,e taret o&ect. 5hat happens to the more6massive attac,ing ob7ect8 o o 5hat happens to the less6massive target ob7ect8 Investigate the action of a le""%$a""#,e attac-#! o&ect "tr#-#! a $ore% $a""#,e taret o&ect. o 5hat happens to the less6massive attac,ing ob7ect8 5hat happens to the more6massive target ob7ect8 o •
Complete the below tables with the b' imputing ,nowns and pressing the pla' button. 0a"" 1-2
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4 E1
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1- $/ "2 •
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To tal Initi al+ To tal %in al+
3oes conservation of energ' occur in this collision8
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0a"" O
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1-2
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9.=4
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=.;4
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4 E1
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J 2
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1- $/ "2 •
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To tal Initi al+ To tal %in al+
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3oes conservation of energ' occur in this collision8
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The total initial momentum for the collision below is //.:. 5hat is the initial velocit' of ob7ect /8
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1-2
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9.:4
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1- $/ "2 •
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9 •
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4. ;: 4
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To tal Initi al+ To tal %in al+
3oes conservation of energ' occur in this collision8
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)ER*ECTL+ INELASTIC COLLISION: !et the elasticit' setting in the upper right corner panel to 4.4. Pla' with the simulator and note a few observations comparing an elastic and inelastic collision. •
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Complete the below tables with the b' imputing ,nowns and pressing the pla' button. 0a""
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1-2
V #
V
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!#t#al
3!al
!#tal
1$/" 2
1$/" 2
1- $/" 2
) 3! al
1-
4 E1 J 2
$/ "2 •
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/.94
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/.94
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/ •
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9
/. :4 6 /.; 4
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To tal Initi al+ To tal %in al+
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0a"" 1-2
O
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V #
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9.=4
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=.;4
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/ •
9 •
V
)#
!#t#al
3!al
!#tal
1$/" 2
1$/" 2
1- $/" 2
/. >4 4. 4
)
4 E1
3!
J 2
al
1- $/ "2 •
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3oes conservation of energ' occur in the collisions above8
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CONCLUSION QUESTIONS: /. @ collision where both momentum and ,inetic energ' are conserved is an elastic / inelastic collision. 9. @ :44. gram cart moving at .>A4 m-s) what is its momentum8 • • •
If the cart was to bounce oB a wall and return with a velocit' of 6.9=4 m-s) what is its Impulse be8 •
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>.
To tal Initi al+ To tal %in al+
=. @ .9>4 ,g baseball is thrown with a speed of =/ m-s. 5hat is the balls momentum8 • • •
If the above ball comes to rest in the catchers mitt in .4;: seconds) how much force does the ball appl' on the catchers mitt8 #hint+ use the impulse6 momentum theorem & •
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:. Imagine 'ou are ice s,ating with 'our 2%%. 2oth of 'ou at rest) when 'ou shove him-her awa' from 'ou. ou have a mass of A: ,g and he-she has a mass of ::,g. 5hen 'ou shove oB) 'ou move awa' with a velocit' of 9.4 m-s. 5ith what velocit' does 'our 2%% move awa' from 'ou8 • • • • • • • •
A. If a 9:4. gram cart moving to the right with a velocit' of (.>/ m-s collides inelasticall' with a :44. gram cart traveling to the left with a velocit' of %.99 m-s) what is the total momentum of the s'stem before the collision8 • • • •
5hat is the resulting velocit' of the above two6car s'stem #stuc, together&8 •
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D. @ ?.4 ,g bowling ball races down the lane at /: m-s before stri,ing a bowling pin #at rest& with a mass of .;: ,g. If the .;: ,g pin bounces bac,ward with a velocit' of =: m-s) what is the velocit' of the bowling ball after the collision8 • • • • •
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;. If two automobiles collide, they usually do not stick together !oes this mean the collision is elastic" #$%lain • • • • • • •
?. 5hat happens when two ob7ects collide at an angle8
