PASCO ME-9283 User Manual

Instruction Manual and
Experiment Guide for
the PASCO scientific
Model ME-9283

TAPE TIMER

012-04944B

2/93

ME-9283

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Copyright © January 1993 $5.00

012-04944B Tape Timer

T able of Contents

Section Page

Copyright, Warranty, and Equipment Return............................................... ii-iii

How to Use this Manual ..................................................................................1

Introduction .....................................................................................................1

Features............................................................................................................2

Equipment........................................................................................................3

Setup and Operation ........................................................................................ 4

Experiment: Acceleration Due to Gravity .......................................................5

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Tape Timer 012-04944B

Copyright, Warranty and Equipment Return

Please—Feel free to duplicate this manual
subject to the copyright restrictions below.

Copyright Notice

The PASCO scientific Model ME-9283 Tape Timer
manual is copyrighted and all rights reserved. How­ever, permission is granted to non-profit educational
institutions for reproduction of any part of this manual
providing the reproductions are used only for their
laboratories and are not sold for profit. Reproduction
under any other circumstances, without the written
consent of PASCO scientific, is prohibited.

Limited Warranty

PASCO scientific warrants this product to be free
from defects in materials and workmanship for a
period of one year from the date of shipment to the
customer. PASCO will repair or replace, at its option,
any part of the product which is deemed to be defec­tive in material or workmanship. This warranty does
not cover damage to the product caused by abuse or
improper use. Determination of whether a product
failure is the result of a manufacturing defect or
improper use by the customer shall be made solely by
PASCO scientific. Responsibility for the return of
equipment for warranty repair belongs to the cus­tomer. Equipment must be properly packed to prevent
damage and shipped postage or freight prepaid.
(Damage caused by improper packing of the 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.

Equipment Return

Should the product have to be returned to PASCO
scientific for any reason, notify PASCO scientific by
letter, phone, or fax BEFORE returning the product.
Upon notification, the return authorization and
shipping instructions will be promptly issued.

ä

NOTE: NO EQUIPMENT WILL BE

ACCEPTED FOR RETURN WITHOUT AN
AUTHORIZATION FROM PASCO.

When returning equipment for repair, the units
must be packed properly. Carriers will not accept
responsibility for damage caused by improper
packing. To be certain the unit will not be
damaged in shipment, observe the following rules:

➀ The packing carton must be strong enough for the

item shipped.

➁ Make certain there are at least two inches of

packing material between any point on the
apparatus and the inside walls of the carton.

➂ Make certain that the packing material cannot shift

in the box or become compressed, allowing the
instrument come in contact with the packing
carton.

Address: PASCO scientific

10101 Foothills Blvd.
Roseville, CA 95747-7100

Phone: [phone]
FAX: [phone]
email: [e-mail]
web: www.pasco.com

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012-04944B Tape Timer

Introduction

The PASCO Model ME-9283 Tape Timer easily and
accurately measures the motion of an object at two
pre-calibrated frequencies. A slower setting (10 Hz)
lends itself to most dynamics cart experiments,
whereas the faster setting (40 Hz) is ideal for free fall
experiments.

ME-9283

TAPE

TIMER

Hz

40 10OFF

9V BATTERY

REMOVE

BOTTOM COVER

This timing method is a visual demonstration of speed
and acceleration. A moving object pulls a paper tape
through the timer which prints dots on the tape at even
time intervals. The result is a series of dots in a line on
the paper tape representing the position of the object as
a function of time. From the dots on the tape, the
distance traveled can be measured and the average
speed for each time interval calculated.

The tape can be attached to air track carts, dynamics
carts, or falling masses.

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Tape Timer 012-04944B

Features

Rod clamp

Carbon paper disk

Paper tape

Battery compartment

for 9V Battery (internal)

Thumb screw

Strike plate

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Hammer

(not visible when strike

plate is attached)

Guide slots

ME-9283

Time interval

selection switch

(10 Hz or 40 Hz)

Power adapter jack

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012-04944B Tape Timer

Equipment

The Tape Timer includes the following items

• ME-9283 apparatus

• (10) Carbon paper disks

• Roll of paper tape

• 9 V battery

• Instruction manual

Additional Equipment Available:

• 9 V DC Power Supply/Adapter

ME-9283 Tape Timer

ME-9283

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Additional supplies required to perform the
Experiment:

– Table clamp and rod
– Hooked Mass, 200 g
– Masking tape
– Graph paper

9 V Battery

Paper tape

Carbon paper disks

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Tape Timer 012-04944B

Setup and Operation

Inserting or Replacing the Carbon Paper

➀ Remove the thumb screw and the strike plate from

the top of the Tape Timer.

➁ If applicable, remove the used carbon paper and

discard it.

➂ Turn the strike plate over. With the carbon side fac-

ing toward the strike plate, center the hole of the new
carbon paper disk over the peg on the strike plate.

➃ Turn both the strike plate and the carbon disk to

their original orientation and fasten the strike plate
in its place on top of the timer with the thumb
screw. Be sure the carbon disk can rotate freely so
the hammer will strike the disk in a circular pattern

Thumb screw

Strike plate

Peg

Carbon paper disk

Carbon side

Hammer

rather than in just one spot.

Inserting the Paper Tape

➄ Cut the paper tape to the length required to span the

motion of the object.

➅ Thread one end of the paper tape through both pa-

per guides, between the strike plate and the carbon
paper disk. (The paper tape passes over the top of
the carbon disk.)

➆ Attach one end of the paper tape to the object and

place the apparatus so
the tape is in line with
the motional direction
of the object.

Direction of

object motion

ME-9283

TAPE

TIMER

Hz

40 10OFF

9V BATTERY

REMOVE

BOTTOM COVER

Using the Tape Timer

➇ Turn the selector switch to the desired frequency

and set the object in motion. While the object is
pulling the tape through the timer, the hammer hits
the strike plate at even time intervals. Each hit pro­duces a dot on the paper transferred through the
carbon paper.

➈ To analyze the data, record the positions of the dots

on the tape. Average speeds can be calculated us­ing the distances between adjacent dots divided by
the time interval.

Paper tape

Carbon dots

Measured

distance

➉ When the dots become faint, move the carbon disk

so the hammer will strike it in a new spot. To do so,
loosen the thumb screw that holds the strike plate
on top of the timer, slide the strike plate to a new
position, and tighten the thumb screw. The carbon
disk moves with the strike plate.

Battery Replacement

➀ Turn the timer box over and loosen the thumb

screw on the bottom of the box.

➁ Remove the bottom of the box. Unclip and replace

the 9 V battery with a new one.

➂ Replace the bottom of the box and tighten the

thumb screw.

Battery

compartment

(PCB)

Battery

clip

Thumb

screw

Battery

Lid

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012-04944B Tape Timer

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∆

Experiment: Acceleration Due to Gravity

EQUIPMENT NEEDED

– Tape Timer with paper tape – Hooked mass 200 g
– Table clamp and rod – Masking tape
– Graph paper

Purpose

The purpose of this experiment is to determine the acceleration due to
gravity.

Theory

A mass attached to one end of the tape is allowed to drop. The dots printed
on the tape as it passes through the Tape Timer record the position of the
mass as a function of time.

To find the acceleration due to gravity, graph the average speed versus
time. To calculate the average speeds for each time interval, use

x

v =

∆t

The slope of the resulting straight line is equal to the acceleration due to
gravity

v

g =

∆t

Setup

➀ Clamp the Tape Timer to the edge of a table using the rod and table clamp.

Orient the Tape Timer on its side so the tape can pass through the Tape
Timer vertically. (See Figure.)

➁ Cut a piece of paper tape as long as the distance between the timer and the

floor.

➂ Make a loop with one end of the paper tape by folding it over and securing

it with a piece of tape. Hook the 200 g mass on the loop end of the paper
tape.

(held by hand)

Tape

Timer

Hooked

mass

Floor

Paper tape

Table

Table

clamp

➤NOTE: If the mass used is too small, it will not give accurate results because of air drag
and friction on the paper tape.

Procedure

➀ Thread the other end of the paper tape through the Tape Timer until the mass is at the level of the

Timer.

➁ Hold the paper tape vertically above the Timer and turn on the Timer to 40 Hz.
➂ Drop the tape, allowing the mass to fall.
➃ Tape the paper tape to a table and measure the positions of each of the dots. Don’t use the

first dot because the mass may not have begun to move when the dot was made.

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Tape Timer 012-04944B

∆

Record the positions in Table 1.

Table 1 Data and Analysis

Position (cm) ∆x (cm) Avg. v (cm/s) t (sec)

Analysis

➀ Calculate the distance (∆x) between dots by subtracting the positions of adjacent dots. Record in

Table 1.

➁ Calculate the average speed using

x

v =

∆t

where ∆t is the time between dots.
Since the Tape Timer was set on 40 Hz, it was making 40 dots per second which means that the

time between dots is 1/40 second or 0.025 seconds. Record the average speeds in Table 1.

➂ Write down the time that each average speed occurred in the last column of Table 1. These are

the elapsed times, not the time intervals. Assume that the first average speed occurred at time
zero. The beginning of the timing is arbitrary since it will not affect the resulting slope of the
line.

➃ Plot the average speed versus time on graph paper.
➄ Draw the best-fit straight line and find its slope.

slope = g = _______________________

➅ Calculate the percent difference between the slope and the accepted value for g.

% difference = ____________________

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012-04944B Tape Timer

T echnical Support

Feed-Back

If you have any comments about this product or this
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 feed-back. Your input helps us evaluate and
improve our product.

To Reach PASCO

For Technical Support call us at 1-800-772-8700 (toll­free within the U.S.) or [phone].

Contacting Technical Support

Before you call the PASCO Technical Support staff it
would be helpful to prepare the following information:

• If your problem is computer/software related, note:
Title and Revision Date of software.
Type of Computer (Make, Model, Speed).
Type of external Cables/Peripherals.

• If your problem is with the PASCO apparatus, note:
Title and Model number (usually listed on the label).
Approximate age of apparatus.

A detailed description of the problem/sequence of
events. (In case you can't call PASCO right away,
you won't lose valuable data.)

If possible, have the apparatus within reach when
calling. This makes descriptions of individual parts
much easier.

• If your problem relates to the instruction manual,

note:
Part number and Revision (listed by month and year

on the front cover).

Have the manual at hand to discuss your questions.