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Physical Pendulum Accessory

Model No. ME-9858

6

®

Taking Measurements and Collecting Data

Part I: Measure and Adjust the Mass of the Car

1. 

Release the car from halfway up the hill and carefully watch the collision.  If the car has no 

added masses, it will rebound off of the pendulum, and thus be moving "backwards" after the 
collision.  If the ballast mass was added, the car would continue in the forward direction after 
the collision. (Here is a good reason to use the catcher at the end of the track as a safety stop.)

CAUTION: 

Catch the pendulum before it swings back down!  Don't let it swing down 

and hit the car!

2. 

With the small screw provided with the car, secure the 

small masses in the tray on top of the bumper (Figure 4.)

3. 

 Using the small masses provided, adjust the mass of the 

car so that after the collision, the car is neither moving 
forwards or backwards.  The car should stop completely, 
so that its velocity after the collision is zero.  The mass 
needed to do this is independent of the speed of the car, 
but if the car is moving too slowly, friction will stop the 
car any way.  Start the car at least half way up the hill 
during this part of the experiment.

4. 

 After adding the proper amount of mass, weigh the mass of the entire car (m

o

).

Part II: Record the Pendulum’s Mass, 

Length, and Radius

1. 

Find the pendulum's mass (M).  (Note: This 

does 

not

 include the pivot support rod.)

2. 

Measure the length (

l

) of the brass part of the 

pendulum.  Do 

not

 include the bumper pin.

3. 

Measure the distance (d) from the center of the 

pivot pin to the top end of the pendulum (the 
non-pin end) (See Figure 5).

4. 

With the pendulum on the support pivot, and 

the car's bumper against bumper pin, measure 
the distance (

r

) from the center pivot pin out to 

the position of the rubber bands on the car 
bumper.  This is the radius at which the car applies a force (and thus a torque) to the 
pendulum, causing it to rotate.  Note:  Because of the bumper pin, 

l

=d+r.

mass

screw

Figure 4: Mass in Car

pivot

rubber

d

r

band

bumper

Figure 5

l

Содержание Physical Pendulum Accessory

Страница 1: ...Instruction Manual Manual No 012 08581A Physical Pendulum Accessory Model No ME 9858...

Страница 2: ......

Страница 3: ...r 6 Part II Record the Pendulum s Mass Length and Radius 6 Part III Collecting Velocity Data 7 Option 1 Measuring the Car s Velocity with Photogates and a Computer Interface 7 Option 2 Measuring the C...

Страница 4: ...with pivot pin 1 003 08577 2 Pivot Rod with Ball Bearings 1 616 101 3 Mass 1 gram 2 648 06505 4 Mass 2 grams 2 648 06506 5 Mass 5 grams 1 648 06507 6 Mass 10 grams 1 648 06508 Additional Equipment Req...

Страница 5: ...tudies of angular momentum linear and rotational kinetic energy and gravitational potential energy The release point of the Mini Car can be adjusted until the pendulum just makes it to the top of its...

Страница 6: ...shown in Figure 3a Use two rubber bands b Release the car backwards with the rubber band part of the bumper in front Note The bumper pin on the end of the pendulum must hit the middle of the rubber b...

Страница 7: ...o that its velocity after the collision is zero The mass needed to do this is independent of the speed of the car but if the car is moving too slowly friction will stop the car any way Start the car a...

Страница 8: ...ust the photogate up and down so that the flag blocks the photogate beam The nuts on the photogate support peg allow the sideways position of the photogate to also be changed For more information see...

Страница 9: ...dulum can experimentally be found by balancing it on a knife s edge but since the pins have negligible mass you can assume its center of mass is at the center l 2 Thus the distance x Figure 7 the dist...

Страница 10: ...mass increases its height by an amount h it increases its gravitational potential energy PE by an amount mgh For a non point mass like the physical pendulum the distance h is the amount the center of...

Страница 11: ...tle friction we can assume conservation of energy as the pendulum swings up to its stopped position at the top Thus the pendulum s total energy at the bottom only rotational KE is equal to its total e...

Страница 12: ...come to DataStudio window double click Create Experiment b In the Sensors list click and drag a Photogate icon to the picture of the interface i e to the same digital channel in which you have the pho...

Страница 13: ...on Copyright Notice The PASCO scientific 012 08581A Physical Pendulum Accessory Manual is copyrighted and all rights reserved However permission is granted to non profit educational institutions for r...

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