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012–06734A

Smart Timer

33

Note:  The following experiment is in copy-ready form in the manual for the
Time of Flight Accessory (manual number 012-05088)

• Time of Flight and Initial

Velocity ( Experiment 1):

Use the Smart Timer instead of a

Photogate Timer, and set the

Smart Timer to measure Time,

Two Gates.  Be sure the plug

from the Photogate is connected

to channel 1 of the Smart Timer

and the plug from the Time of

Flight Accessory is connected to

channel 2 (see Figure 9.1). Press

 to activate the Smart Timer

and fire the launcher.

Note:  The following experiment is  in copy-ready form in the manuals for the
Mini Launcher (manual number 012-05479) and the Ballistic Pendulum/
Projectile Launcher (manual number 012-05375)

• Projectile Motion Using

Photogates ( Experiment 2):

Use the Smart Timer instead of a

computer and IDS Timer

software, and set the experiment

up as directed in the experiment.

Plug the photogates into the

Smart Timer as shown in Figure

8.1, and set up the Smart Timer

to measure Time, Two Gates.

Press 

 to activate the Smart

Timer and fire the launcher.

Calculate the initial velocity

using the time required for the

ball to pass through the

photogates.

ME-6800

SHORT RANGE

PROJECTILE LAUNCHER

WEAR
SAFETY
GLASSES –
WHEN IN USE.

CAUTION!

DO NOT LOOK

DOWN BARREL!

CAUTION!

DO NOT LOOK

DOWN BARREL!

Projectile
Launcher

Photogate
Mounting Bracket

To Smart Timer
channel 1

To Smart Timer
channel 2

Time of Flight
Accessory

Figure 9.1

Setup for the 

Timer of Flight and Initial Velocity Experiment

Photogates

To Smart Timer
channel 2

To Smart Timer
channel 1

ME-6825 Mini Launcher
(or ME-6800 Projectile
Launcher)

Figure 8.1

Setup for the 

Projectile Motion Using Photogates Experiment

Photogate
Mounting
Bracket

Содержание ME-8932

Страница 1: ...1998 PASCO scientific 7 50 Instruction Manual and Experiment Guide for the PASCO scientific Model ME 8930 012 06734A 09 98 SMART TIMER Plane4...

Страница 2: ...Smart Timer 012 06734A...

Страница 3: ...SpeedMeasurementModes 7 Table 1 Summary of Timing Modes 8 9 AccelerationMeasurementModes 10 Count Modes 10 Test Mode 11 Timing Diagrams 11 LOCK Switch 11 Caring for the Smart Timer 12 Specifications 1...

Страница 4: ...he equipment for return shipment will not be covered by the warranty Shipping costs for returning the equipment after repair will be paid by PASCO scientific Copyright Warranty and Equipment Return Pl...

Страница 5: ...existing timing options The Smart Timer s internal microcontroller also eliminates the problem of incorrect readings due to multiple passes through the same photogate by understanding the type of mea...

Страница 6: ...to a glide or Dynamics Cart the Smart Timer and Smart Pulley can be used to determine linear acceleration cm s2 as well Note The use of pulleys with different diameters and or different number of spo...

Страница 7: ...display touchpad keys mode illustrations on off switch side panel battery compartment bottom panel input channel 2 input channel 1 connector for 9VDC adapter side panel 9 VDC adapter Figure 1 Include...

Страница 8: ...measurement until both the type and mode have been selected 3 Once a complete measurement has been selected press Start Stop to begin You will hear a beep and a asterisk will appear on the second lin...

Страница 9: ...012 06734A Smart Timer 5...

Страница 10: ...essing Start Stop will stop the measurement and any recorded times will be displayed Two Gates In this mode the Smart Timer measures the time between blocking two photogates This mode is useful for no...

Страница 11: ...iming with the Start Stop key and end it with a photogate block or vice versa 4 If a photogate is plugged in and blocked when you try to use the Start Stop key as a stopwatch the Smart Timer will be t...

Страница 12: ...Gate Fence Two Gates Pendulum Stop Watch One Gate cm s Collision cm s Pulley rad s Pulley rev s Table 1 Summary of Smart Timer Modes Time Speed Type Modes Key Sequence Timing Diagram Calculation Algor...

Страница 13: ...One Gate Linear Pulley Angular Pulley Two Gates 30 seconds 60 seconds 5 minutes Manual One Gate Acceleration Counts Test The key sequences shown are valid in the initial or power on situation only...

Страница 14: ...e the radians second measurement there is a two second maximum time for two photogate blocks translating to a minimum speed of 0 05 rev s Also note that accuracy decreases rapidly as pulley speeds inc...

Страница 15: ...owered as long as the top line of the display reads Test Gates This mode is useful for experiment setup or for testing accessory photogates G M tubes or other Smart Timer accessories Pressing the Sele...

Страница 16: ...ing resolution of the Smart Timer is 100 microseconds in all modes except Stopwatch which is 10 ms Calculated Values Calculated values are displayed to one or two decimal places with typical accuracy...

Страница 17: ...rt Timer so you get more accurate measurements of the free fall time of the steel ball See page 34 Determining the acceleration due to gravity g with the Free Fall Adapter and Figure 10 1 for details...

Страница 18: ...Smart Timer 012 06734A 14...

Страница 19: ...directly To calculate the acceleration from time measurements the following formula must be used Note that Dt is not t2 but is 1 2 t2 see Figure 1 1 Figure 1 1 Explanation of why t2 is used in the for...

Страница 20: ...t accuracy 1 The Picket Fence must be dropped at a 90 angle to the photogate beam in such a way that it does not rotate on the way down One method to improve the drop is to hold the edge of the Picket...

Страница 21: ...g assuming that friction is negligible According to Newton s Second Law this net force should be equal to ma where m is the total mass that is being accelerated which in this case is m1 m2 This experi...

Страница 22: ...will begin when the photogate beam is first blocked Repeat this measurement 3 times with the same masses Record all the values in Table 2 1 Calculate the average accelerations and record in Table 2 1...

Страница 23: ...er accomplished in this experiment using the Velcro patches on one end of each cart Procedure PARTA Inelastic Collisions 1 Level the track by setting a cart on the track to see which way it rolls Adju...

Страница 24: ...e of the track Give the other cart an initial velocity toward the cart at rest b Start both carts at one end of the track Give the first cart a slow velocity and the second cart a faster velocity so t...

Страница 25: ...e total momentum of the carts before and after the collision and record in the table Questions Table 3 2 Results 1 When two carts moving toward each other have the same mass and the same speed they st...

Страница 26: ...ut two mass bars in one of the carts so that the mass of one cart 3M is approximately three times the mass of the other cart 1M Weigh the carts and record the masses in Table 3 3 a Place the 3M cart a...

Страница 27: ...al 3 Trial 4 Trial 5 Trial 6 Trial 7 Table 3 4 Results Questions 1 Kinetic energy is not conserved in inelastic collisions but it is conserved in ideal elastic collisions For one of the collisions cal...

Страница 28: ...Smart Timer 012 06734A 24...

Страница 29: ...theoreticalvalues Theory Theoretically the rotational inertia I of a ring about its center of mass is given by where M is the mass of the ring R1 is the inner radius of the ring and R2 is the outer ra...

Страница 30: ...rT where r is the radius of the 3 Step Pulley about which the thread is wound and T is the tension in the thread when the apparatus is rotating Applying Newton s Second Law for the hanging mass m giv...

Страница 31: ...he acceleration of the ring and disk using a hanging mass of about 50 g Wind the thread up and let the mass fall Record the acceleration press when the mass has fallen about 1 3 of the total fall dist...

Страница 32: ...ving only the rotational inertia of the ring To do this take the ring off the rotational apparatus and repeat step 2 using a hanging mass of approximately 30 g 5 Remove the disk from the shaft and rot...

Страница 33: ...onal inertia of the ring and disk Note This calculation will be the rotational inertia of the ring alone 5 Calculate the experimental value of the rotational inertia of the disk about its diameter 6 C...

Страница 34: ...Smart Timer 012 06734A 30...

Страница 35: ...12 05035 Acceleration Down an Incline Experiment 8 Use a Photogate and the Smart Timer instead of a stop watch Figure 5 1 Adjust the height of the Photogate so the light path is intersected with the 5...

Страница 36: ...t oscillations and activate the Smart Timer to measure the period of oscillation Note The following experiment is in copy ready form in the manual for the Introductory Dynamics System with Computer Ti...

Страница 37: ...riment 2 Use the Smart Timer instead of a computer and IDS Timer software and set the experiment up as directed in the experiment Plug the photogates into the Smart Timer as shown in Figure 8 1 and se...

Страница 38: ...or 2 of the Smart Timer Figure 10 1 Set up the Stopwatch mode of the Smart Timer Press once The Smart Timer is now activated and will record the time the interval between the release of the ball and...

Страница 39: ...pasco com Contacting Technical Support Before you call the PASCO Technical Support staff it would be helpful to prepare the following information If your problem is with the PASCO apparatus note Titl...

Страница 40: ......

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