Page 3 - Table of Contents; Section
01206734A Smart Timer Table of Contents Section Page i Table of Contents .......................................................................................................................... i Copyright, Warranty, and Equipment Return ..............................................................
Page 4 - ii; Copyright Notice; Copyright, Warranty, and Equipment Return; Please; Feel free to duplicate this manual; Equipment Return; NO EQUIPMENT WILL BE
ii Copyright Notice The PASCO scientific 012-06734A Smart Timermanual is copyrighted and all rights reserved. However,permission is granted to non-profit educationalinstitutions for reproduction of any part of the manualproviding the reproductions are used only for theirlaboratories and are not sold...
Page 5 - Introduction; that indicates the operating mode and experimental results.
012–06734A Smart Timer 1 Introduction The PASCO ME-8930 Smart Timer is an accurate, versatile digital timer and measurement system for the student laboratory. The Smart Timer offers 0.1 ms timing resolution and an easy-to-use memory function. The Smart Timer measures several types of events detected...
Page 6 - Use with the Smart Pulley:
Smart Timer 012–06734A 2 In One Gate Mode, a single photogate lets you measure the time, velocity, or acceleration of a fence as it passes through the photogate. Two photogates are used for collision experiments using one or two carts or for experiments where the velocity of a cart must be measured ...
Page 7 - Equipment; Included equipment
012–06734A Smart Timer 3 Plane4 Equipment Included: Smart Timer Smart Timer Picket Fences (2) 9 VDC adapter liquid crystal 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 VD...
Page 8 - Operating the Smart Timer; Plug the 1⁄4-inch phone plug from the photogate into the; Smart Timer Modes of Operation; Figure 2; Note: Smart Timers shipped to certain
Smart Timer 012–06734A 4 Pla ne4 Operating the Smart Timer 1. Plug the ¼-inch phone plug from the photogate into the Smart Timer’s input channel 1 or 2 (see Figure 2). For all experiments using a single photogate or pulley, either of the two available jacks may be used interchangeably. For all other...
Page 10 - Time Modes
Smart Timer 012–06734A 6 summary of the mode suggested for a given experimental activity can be found on page 5 (Quick Cross-Reference for Suggested Activities and Smart Timer Modes). Refer to the timing diagrams in Table 1 (pages 8 and 9) for a detailed look at how the Smart Timers times events on ...
Page 11 - Notes about the Stopwatch Mode:; Speed Modes
012–06734A Smart Timer 7 cleared and the “*” reappears. This RESET-START-STOP sequence is repeated for each new elapsed time. Whenever the “*” is not showing, the mode may be changed. Using the Alternate Timing Function: Connect an appropriate accessory to input channel #1 or #2. Enter Stopwatch mod...
Page 12 - Table 1. Summary of Smart Timer Modes; Time; Type
One 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 Algorithm
Page 13 - * The key sequences show
One Gate Linear Pulley Angular Pulley Two Gates 30 seconds 60 seconds 5 minutes Manual One Gate Acceler a tion Counts Te st * The key sequences show n are valid in the initial or power-on situation only.
Page 14 - Acceleration Modes; to an equivalent linear acceleration in cm/s
Smart Timer 012–06734A 10 Pulley (rad/s): The Smart Timer will measure the speed of a pulley passing through a photogate in units of radians/second. One measurement will be taken each time the Start/ Stop switch is pressed. The Smart Timer cannot differentiate between clockwise and counterclockwise ...
Page 15 - Test Mode; Figure 3
012–06734A Smart Timer 11 timing interval. If you wish to stop the count during a timing interval, press Start/ Stop. The display will freeze the current count and the “*” will disappear from the first column. At this time you may select a new measurement or start a new timing interval. The maximum ...
Page 16 - Caring for the Smart Timer; Strong ultraviolet light can damage the Smart Timer display.; Specifications; Timer. See the current PASCO catalog for more information.
Smart Timer 012–06734A 12 Caring for the Smart Timer • Do not use a pointed object (such as a pen) to press the keypad buttons. Wrap the Smart Timer separately when transporting it with other items. The transparent covering over the keypad can be creased by a fingernail or other sharp object. • Clea...
Page 19 - Experiment One: Acceleration Due to Gravity; EQUIPMENT AND MATERIALS REQUIRED; Smart Timer Picket Fence; Purpose; Note that; Explanation of why 1⁄2 t; Procedure; PART A—Determining the acceleration from time and; Mount the photogate on a stand, or hold the Photogate; Experiment setup; where
012–06734A Smart Timer 15 Experiment One: Acceleration Due to Gravity EQUIPMENT AND MATERIALS REQUIRED Smart Timer (ME-8930) Smart Timer Picket Fence Photogate (ME-9498A) Purpose The purpose is to determine the acceleration due to the Earth’s gravity. Theory The accepted value for the accelera...
Page 20 - Questions; through the photogate.; PART B—Determining the acceleration directly.
Smart Timer 012–06734A 16 Questions 1. How do the two methods for determining the acceleration on a body due to Earth’s gravity compare? 2. How do the experimental measurements compare to accepted values? 2. Insert the plug of the photogate into channel 1 or 2 of the Smart Timer, and set up the Smar...
Page 21 - Experiment Two: Newtons Second Law; mass m; . This experiment will; check to see if m; rest on the track will not move toward either end.; Experiment setup to determine the acceleration of the masses
012–06734A Smart Timer 17 Experiment Two: Newtons Second Law EQUIPMENT AND MATERIALS REQUIRED Smart Timer (ME-8930) Photogate (ME-9498A) Dynamics Cart (ME-9430 or ME-9454) Photogate Bracket (part no. 003-04662) Dynamics Cart Track (ME-9429A) Mass Hanger and Mass Set (ME-9348) 500 gram...
Page 22 - Set up the Smart Timer to record Acceleration: Linear Pulley.; Analysis; Why is the mass in F = ma not just equal to the mass of the cart?; theoretical – measured; cart
Smart Timer 012–06734A 18 5. Place the Dynamics Cart on the track, attach a string to the hole in the end of the cart, and tie a mass hanger on the other end of the string. The string must be just long enough so the cart hits the end stop before the mass hanger reaches the floor. 6. Pull the cart ba...
Page 23 - Experiment Three: Conservation of Momentum In Collisions; EQUIPMENT AND MATERIALS REQUIRED; balance; using the Velcro patches on one end of each cart.; PART A: Inelastic Collisions; on the track will not move.; Experiment setup for
012–06734A Smart Timer 19 Experiment Three: Conservation of Momentum In Collisions EQUIPMENT AND MATERIALS REQUIRED Smart Timer (ME-8930) (2) Photogate (ME-9498A) Collision Cart with mass (2) (ME-9454) (2) Photogate Bracket (Part No. 003-04662) Dynamics Cart Track (ME-9429A) (2) Smart Ti...
Page 24 - to activate the; Equal Masses; ir
Smart Timer 012–06734A 20 3. Set up the Smart Timer to measure Speed: collision (cm/s). Press to activate the Smart Timer. ➤ Note: If the flags of both carts do not go through the photogate beams twice, the Smart Timer will not complete the timing cycle and display velocitiesautomatically. You will ...
Page 25 - the carts before and after the collision and record in the table.
012–06734A Smart Timer 21 Analysis 1. For each of the cases, calculate the momentum of each cart before the collision. Record the results in Table 3.2. 2. For each of the cases, calculate the total momentum of both carts before the collision. Record the results in Table 3.2. 3. For each of the cases...
Page 26 - Part B—Elastic Collisions; Unequal Masses; velocity toward the cart at rest.
Smart Timer 012–06734A 22 Part B—Elastic Collisions Set up the carts so the magnetic ends face each other, so the carts will repel each other when they collide. Record the data in Tables 3.3 and 3.4. Equal Masses a. Place one cart at rest in the middle of the track. Give the other cart an initial ve...
Page 29 - Experiment Four: Rotational Inertia of a Disk and Ring; EQUIPMENT REQUIRED; calipers; where M is the mass of the ring, R; M R; Disk rotating about its center of mass
012–06734A Smart Timer 25 Experiment Four: Rotational Inertia of a Disk and Ring EQUIPMENT REQUIRED Rotating Platform (ME-8951) Ohaus Triple-Beam Balance (DE-8707) or similar Rotational Inertia Accessory (ME-8953) paper clips (for masses < 1 g) Smart Pulley (ME-9387) calipers Smart ...
Page 30 - resulting angular acceleration is measured. Since; Rotational Apparatus and Free-Body Diagram; Solving for the tension in the thread gives:
Smart Timer 012–06734A 26 I = τ α To find the rotational inertia experimentally, a known torque is applied to the object and the resulting angular acceleration is measured. Since t = I a , where a is the angular acceleration, which is equal to a/r, and t is the torque caused by the weight hanging fr...
Page 31 - Mass of Ring; Table 4.1. Theoretical Rotational Inertia Data; thread up and let the mass fall. Record the acceleration (press; Setup; that has the indentation for the ring should be up.; Measurements for the Theoretical Rotational Inertia; and R
012–06734A Smart Timer 27 Mass of Ring Mass of Disk Inner Radius of Ring Outer Radius of Ring Radius of Disk Table 4.1. Theoretical Rotational Inertia Data Accounting for Friction 1. Set up the Smart Timer to measure Speed, Pulley (rev/s). 2. Tie several paper clips onto the string that hangs over t...
Page 32 - and calculate the radius.; Disk mounted vertically; Ring and Disk
Smart Timer 012–06734A 28 least three times and record the average values for weight of the hanging mass and acceleration in Table 4.2. 3. Using calipers, measure the diameter of the pulley about which the thread is wrapped and calculate the radius. 4. Since in step 2, the disk is rotating as well a...
Page 33 - Calculations; Record the results of the following calculations in Table 4.3.; Theoretical
012–06734A Smart Timer 29 Calculations Record the results of the following calculations in Table 4.3. 1. Subtract the “friction mass” from the hanging mass used to accelerate the apparatus to determine the mass, m, to be used in the equations. 2. Calculate the experimental value of the rotational in...
Page 35 - Other Suggested Experiments; Setup for the
012–06734A Smart Timer 31 • Simple Harmonic Oscillator (Experiment 3): Use a Photogate and the Smart Timer instead of a stop watch, and use the ME-9471 Picket Fence (part number 648-04704) , not the Smart Timer Picket Fence (Figure 6.1). Set up the Smart Timer to measure Time, Pendulum. Press to act...
Page 37 - Two Gates. Be sure the plug
012–06734A Smart Timer 33 Note: The following experiment is in copy-ready form in the manual for theTime 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...
Page 38 - Setup for counting radiation with the SN-7927 G-M Tube/Power Supply
Smart Timer 012–06734A 34 • Counting radiation with the G-M Tube/Power Supply (SN-7927) Insert the plug of the G-M Tube/ Power Supply into channel 1 or 2 of the Smart Timer (Figure 11.1) Set up the Smart Timer to measure Counts, 30 seconds, 60 seconds, 5 minutes, or Manual. Press to activate the Sma...
Page 39 - Technical Support; Feedback
012–06734A Smart Timer 35 Technical Support Feedback If you have any comments about the product or manual, please let us know. If you have any suggestions on alternate experiments or find a problem in the manual, please tell us. PASCO appreciates any customer feedback. Your input helps us evaluate a...
