Ticker – Timer Practical Repor

Ticker – Timer Practical Report

Introduction
This practical is investigating the motion of a trolley as it is placed at the top of an inclined ramp, and is released to roll down the ramp. With the aid of a ticker-timer, the average speed and acceleration can be determined, and using this data, the amount of force that the trolley has acting on it, can be calculated. The ticker-timer is utilised to determine the distance that the trolley travels in each interval of time (0.

1s), and this can be determined by the dots that are marked on the ticker-timer tape. To further investigate in this practical, Newton’s first two Laws of Motion are noted.

Newton’s first law of motion is that an object at rest, will remain at rest unless acted upon by an unbalanced force and that an object in motion will remain in motion, unless acted upon by an unbalanced force.

(Physicsclassroom.com, 2018). In relation to this practical, the trolley will remain at rest, unless acted upon by an unbalanced force. The trolley is held at the top of the inclined ramp, and when it is released, the unbalanced force that is acting on the trolley, is gravity. Gravity acts on the trolley and causes it accelerate and gain speed, thus resulting in the trolley travelling down the ramp.

Newton’s second law of motion, is that the acceleration of an object is dependent upon two variables. These two variables are the net force acting upon the object and the mass of the object.

(Physicsclassroom.com, 2018). In more simplistic terms, force, (F) equals mass, (m), times acceleration, (a), ie F=ma. However, with acceleration as the subject, acceleration equals force divided by mass. In relation to this practical, the trolleys acceleration will be determined by its mass, and the force that gravity exerts on the trolley.

Aim
The aim of this practical is to calculate the average speed and acceleration of the trolley as it travels down the ramp and thus determine the force that the trolley experiences.

Hypothesis
As the trolley travels down the ramp, it will begin to accelerate, and then the pattern created with the dotting of the ticker timer will gradually provide dots with an increased distance between them, because of this acceleration and increased speed.

Variables
The independent variable for this practical experiment was time and the dependent variable was average speed in metres per sec (m/s). There were multiple controlled variables during this practical including the trolley with its weight, the length and height of the ramp and the power supply.

Apparatus:
Retort stand
Trolley
Two boss clamps
Ticker timer
Ticker timer tape

Sticky tape
Carbon paper
DC Power Supply
Two AC wires

Method
Set up apparatus as pictured with ramp measured at height of 30 cm.
Secure the ticker timer at the top on the ramp and connect to the AC plugs of a power box and set to highest volts (12 volts).
Place a piece of carbon paper in the ticker timer facing downwards.
Weigh the trolley car in kilograms, and record.
Measure a piece of ticker tape, and ensure it is approximately an arms length.
Thread one end of the ticker tape through the ticker timer and attach this to the end of the trolley with sticky tape.
Ensure that the trolley is at the top of the ramp (not released, stationary)
Turn the ticker timer on and release the trolley down the ramp.
( Ensure that there will be someone to catch it making it come to a complete stop. )
Check the ticker tape and look for clear dots, not “lines” or “double dots”.
Repeat steps 5 to 8 until there are multiple tapes that are recorded successfully and clearly.

Safety
Make sure there is enough space when performing practical, so the apparatus are not to fall or get knocked over, thus causing damage to property or persons. Ensure trolley is held in position, and practical assistant catching it at end of ramp is notified when trolley is released. This practical was performed with electricity and precautions must take place to make sure this equipment remains out of any contact with water.

Results

Table 1:
Acceleration of trolley travelling down the ramp.
Time (sec)
Distance Travelled (m)
Average Speed (m/s)
0.0
0.000
0.00
0.1
0.020
0.20
0.2
0.042
0.42
0.3
0.068
0.68
0.4
0.094
0.94
0.5
0.118
1.18
0.6
0.143
1.43
0.7
0.163
1.63
0.8
0.189
1.89
0.9
0.196
1.96

Graph of results:

Graph 1:

Discussion:
The aim of this practical was to calculate the average speed and acceleration of the trolley as it travelled down the ramp and thus determining the force that the trolley experienced. The hypothesis of this practical was that as the trolley travels down the ramp, it will begin to accelerate, and then the pattern created with the dotting of the ticker timer will gradually provide dots with an increased distance between them, because of this acceleration and increased speed. The hypothesis was supported by the results, as the speed of the trolley increases, as the distance travelled by the trolley increases. The trolley gains speed, thus accelerating down the ramp, and this is supported by the ticker tape graph, as it is clear that over the same time intervals, the distance travelled by the trolley increases. This is seen in table 1 when comparing the average speed per interval, for example, at 0.1 seconds the trolleys average speed is 0.20 m/s whereas at 0.9 seconds the average speed was 1.96 m/s, this is an increase between 0.8 seconds. In fact, at each time interval the average speed increased thus supporting the hypothesis that the trolley would accelerate throughout its course down the ramp.

Random errors that could have occurred in this practical, would be the that the tape was not inserted correctly into the ticker-timer, thus causing creases or getting caught, hence providing drag which could affect the overall travel of the trolley down the ramp. To minimise the effect of this error, and ensure the set up of the apparatus was correct, test runs were conducted to make sure the practical did not produce this error.
Another error that could have been present in this practical, was when measuring the distance between dots, or between intervals, there could have been multiple perspectives at which the results were read at, hence altering the results. This error could have been minimised if the same measuring device and same examiner was used every time.

An error that could have occurred in this practical, could have been when releasing the trolley there could have been a given force on the trolley. This extra force could have affected the speed of the trolley, thus altering the acceleration of the trolley, hence providing inaccurate results.This could have been minimised, if there was a release button or similar device that could release the trolley with no other external forces applied to the trolley.

To improve the reliability of the results, repetition should take place. If it was repeated when the results are averaged by minimising the effect of random errors. These results were only one take of the experiment. If this practical experiment was repeated several times with more data to analyse then the results give a more accurate reading of acceleration in this practical and less likelihood of errors skewing results.

REFERENCES:

Physicsclassroom.com. (2018). Newton’s First Law. [online] Available at: http://www.physicsclassroom.com/class/newtlaws/Lesson-1/Newton-s-First-Law [Accessed 5 Apr. 2018].

Physicsclassroom.com. (2018). Newton’s Second Law. [online] Available at: http://www.physicsclassroom.com/class/newtlaws/Lesson-3/Newton-s-Second-Law [Accessed 5 Apr. 2018].